Liquid crystal compositions, polymer networks derived therefrom and process for making the same

ABSTRACT

The invention relates to compounds of Formula (I): 
                         
The invention further relates to liquid crystal compositions comprising compounds of Formula (I); compositions further comprising one or more chiral compounds; and polymer networks derived from the polymerization of the liquid crystal compositions. Another embodiment relates to processes for providing compounds of Formula (I).

This application is a division of, and claims the benefit under 35U.S.C.§120 of, U.S. application Ser. No. 11/731,289, filed Mar. 30, 2007,which is by this reference incorporated in its entirety as a part hereoffor all purposes.

This application claims the benefit of U.S. Provisional Application No.60/788,525, filed Mar. 31, 2006, which is incorporated in its entiretyas a part hereof for all purposes.

TECHNICAL FIELD

The present invention is related to the chemical synthesis of bis(meth)acrylate liquid crystal compounds and polymerization of liquidcrystal compositions to provide polymer networks with useful nematic andcholesteric optical properties.

BACKGROUND

Thermotropic liquid crystals are generally crystalline compounds withsignificant anisotropy in shape. That is, at the molecular level, theyare characterized by a rod-like or disc like structure. When heated theytypically melt in a stepwise manner, exhibiting one or more thermaltransitions from a crystal to a final isotropic phase. The intermediatephases, known as mesophases, can include several types of smectic phaseswherein the molecules are generally confined to layers; and a nematicphase wherein the molecules are aligned parallel to one another with nolong range positional order. The liquid crystal phase can be achieved ina heating cycle, or can be arrived at in cooling from an isotropicphase. A comprehensive description of the structure of liquid crystalsin general, and twisted nematic liquid crystals in particular is givenin “The Physics of Liquid Crystals,” P. G. de Gennes and J. Prost,Oxford University Press, 1995.

An important variant of the nematic phase is one wherein a chiral moietyis present, referred to as a twisted nematic or cholesteric phase. Inthis case, the molecules are parallel to each other as in the nematicphase, but the director of molecules (the average direction of therodlike molecules) changes direction through the thickness of a layer toprovide a helical packing of the nematic molecules. The pitch of thehelix is perpendicular to the long axes of the molecules. This helicalpacking of anisotropic molecules leads to important and characteristicoptical properties of twisted nematic phases including circulardichroism, a high degree of rotary power; and the selective reflectionof light, including ultraviolet, visible, and near-IR light. Reflectionin the visible region leads to brilliantly colored layers. The sense ofthe helix can either be right-handed or left-handed, and the rotationalsense is an important characteristic of the material. The chiral moietyeither may be present in the liquid crystalline molecule itself, forinstance, as in a cholesteryl ester, or can be added to the nematicphase as a dopant, with induction of the cholesteric phase. Thisphenomenon is well documented, see e.g. H. Bassler, M. M. Labes, J.Chem. Phys., 52 p 631 (1970).

There has been significant effort invested in the synthesis andpolymerization methods for preparing stable polymer layers exhibitingfixed nematic and/or cholesteric optical properties. One approach hasbeen to synthesize monofunctional and/or polyfunctional reactivemonomers that exhibit a nematic or cholesteric phase upon melting,formulate a low melting liquid crystal composition, and polymerize theliquid crystal composition in its nematic or cholesteric phase toprovide a polymer network exhibiting stable optical properties of thenematic or cholesteric phase. Use of cholesteric monomers alone, asdisclosed in U.S. Pat. No. 4,637,896, provided cholesteric layers withthe desired optical properties, but the polymer layers possessedrelatively weak mechanical properties.

Many efforts have been made to improve the physical properties andthermal stabilities by formulating twisted nematic monomer phases thatare capable of crosslinking polymerizations to provide polymer networks.Examples of these crosslinking monomers are his (meth)acrylates withether groups (—O—) linking a core mesogen to flexible spacers and thepolymerizable (meth)acrylates. Their synthesis and use in formingpolymer networks are disclosed in Makromol. Chem. 190, 2255-2268 (1989);Macromolecules, 1988, 31, 5940; Makromol. Chem. 192, 59-74 (1991); WO1998/047979; J. Polym. Sci.: Part A: Polym. Chem., Vol. 37, 3929-3935(1999); Makromol. Chem. 190, 3201-3215 (1989); U.S. Pat. No. 5,833,880;DE 4,408,170; EP 261,712; EP 331,233 B1; EP 397,263 B1; and JP1994/016616A. Although many of these references also claim ester groups(—C(O)—O—) linking the core mesogen to flexible spacers and thepolymerizable (meth)acrylate, there is limited disclosure in anyreference useful in relation to the teaching of how to make and usebis(meth)acrylates with ester groups (—C(O)—O—) linking the core mesogento flexible spacers and the polymerizable (meth)acrylates. Furthermore,there is limited disclosure in relation to their specific physical orchemical properties.

The preparation of monofunctional (meth)acrylate liquid crystal monomershaving an aliphatic ester group (—C(O)—O—) linking the mesogen to aflexible spacer and the polymerizable (meth)acrylate is disclosed byShibaev, et al, in Polymer Bulletin, 6, 485-492 (1982), and similarcompounds linking a (meth)acrylate to a cholesteryl mesogen via aflexible spacer and an ester moiety are disclosed in U.S. Pat. No.4,614,619. However, since his (meth)acrylate mesogens with esterlinkages have not been prepared, any benefit of the utilities andproperties previously thought to exist for them is difficult to realize.

A need thus remains for a process to make bis(meth)acrylates with esterslinking the mesogen to a flexible spacer and the polymerizable(meth)acrylates. There is also a need for crosslinking monomers thatexhibit nematic and/or cholesteric phases over broad temperature ranges,and there is a need for polymer networks that exhibit cholestericoptical properties.

SUMMARY

One embodiment of the invention is a compound of Formula (I):

wherein R¹ and R² are each independently selected from the group: H, F,Cl and CH₃; n1 and n2 are each independently integers 3 to 20; m and pare each independently integers 0, 1 or 2;

A is a divalent radical selected from the group:

wherein R³-R¹⁰ are each independently selected from the group: H, C1-C8straight or branched chain alkyl, C1-C8 straight or branched chainalkyloxy, F, Cl, phenyl,—C(O)CH₃, CN, and CF₃;

X² is a divalent radical selected from the group: —O—, —(CH₃)₂C—, and—(CF₃)₂C—; and

each B¹ and B² is a divalent radical independently selected from thegroup: R¹¹-substituted-1,4-phenyl, wherein R¹¹ is H, —CH₃ or —OCH₃;2,6-naphthyl; and 4,4′-biphenyl; with the proviso that when m+p is equalto 3 or 4, at least two of B¹ and B² are R¹¹-substituted-1,4-phenyl.

Another embodiment of the invention is a liquid crystal compositioncomprising at least one compound of Formula (I), and in a furtherembodiment the liquid crystal composition includes at least one chiralcompound.

Another embodiment of the invention is a polymer network derived fromthe polymerization of the liquid crystal composition comprising at leastone compound of Formula (I), and in a further embodiment the polymernetwork is derived from polymerization of the liquid crystal compositionincluding at least one chiral compound.

Another embodiment of the invention is a process comprising: (a)providing one or more organic polyol(s) wherein each polyol comprises atleast two hydroxyl groups and at least two covalently bonded carbonatoms, each hydroxyl group being bonded to a different carbon atomwithin an organic polyol; (b) reacting the organic polyol(s) with one ormore functionalized alkyl acid(s) or acid halide(s) of the Formula (V):

wherein X is Cl, Br or —OH; X¹ is selected from the group: Cl, Br, I,-OMs, -OTs and -OTf (as described below); and n is an integer equal to 3to 20; and a first reaction solvent at a first reaction temperature toprovide one or more polyfunctionalized aryl alkanoate ester(s) and afirst spent reaction mixture; and (c) reacting the one or morepolyfunctionalized aryl alkanoate ester(s) with a (meth)acrylate salt inthe presence of a phase transfer catalyst, and a second reaction solventat a second reaction temperature; to provide one or more poly(meth)acrylate-aryl alkanoate ester(s) and a second spent reactionmixture.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the FT-IR spectrum of a polymer network of theinvention having aryl alkanoate ester linkages and a conventionalpolymer network having ether linkages.

DETAILED DESCRIPTION

The terms (meth)acrylate salt, (meth)acrylate ester, (meth)acrylateacid, and the like, herein encompass materials and moieties comprising:methacrylate, for instance wherein R¹ and/or R² is methyl; acrylate,wherein R¹ and/or R² is H; chloroacrylate, wherein R¹ and/or R² is Cl;and fluoroacrylate, wherein R¹ and/or R² is F; unless specificallydefined otherwise.

The term “twisted nematic phase” and “cholesteric phase” and “chiralnematic” herein are synonymous.

Throughout the specification, in Formula (I), when -A- is atrans-cyclohexyl moiety and one or both of m and p is an integer equalto 0, the term “aryl alkanoate ester(s)” can refer to cyclohexylalkanoate ester(s).

One embodiment of the invention is a compound of Formula (I):

wherein R¹ and R² are each independently selected from the group: H, F,Cl and CH₃; n1 and n2 are each independently integers 3 to 20; m and pare each independently integers 0, 1 or 2;

A is a divalent radical selected from the group:

wherein R³-R¹⁰ are each independently selected from the group: H, C1-C8straight or branched chain alkyl, C1-C8 straight or branched chainalkyloxy, F, Cl, phenyl, —C(O)CH₃, CN and CF₃;

X² is a divalent radical selected from the group: —O—, —(CH₃)₂C—, and—(CF₃)₂C—; and

each B¹ and B² is a divalent radical independently selected from thegroup: R¹¹-substituted-1,4-phenyl, wherein R¹¹ is H, —CH₃ or —OCH₃;2,6-naphthyl; and 4,4′-biphenyl; with the proviso that when m+p is equalto 3 or 4, at least two of B¹ and B² are R¹¹-substituted-1,4-phenyl.

Preferably, R¹ and R² are independently selected from H and CH₃, andmore preferably, R¹ and R² are H. Preferably n1 and n2 are eachindependently integers 3 to 10. Preferably, when m and p=2, B¹ and B²are each independently R¹¹-substituted-1,4-phenyl.

In the phrase “each B¹ and B² is a divalent radical independentlyselected from the group.”, when m=2, the two B¹ units are each selectedindependently, that is they may be the same or different; and when p=2,the two B² units are each selected independently, that is they may bethe same or different. In addition, a C1-C8 group may be any one or moreof C₁, C₂, C₃, C₄, C₅, C₆, C₇ or C₈.

The compounds as described above in Formula (I) have a variety of usesin polymerizable liquid crystal compositions. Choices may be made fromwithin and among the prescribed ranges for the variable radicals andsubstituents such that the compound is, for example, either symmetric orasymmetric.

A preferred embodiment of the invention is a compound as described inFormula (I), wherein m and p equal 0, and Formula (I) is selected fromthe group of Formulas (IIa-f):

Compounds as described in Formula (IIa-f) are useful as polymerizablediluents and viscosity modifiers for liquid crystal compositions. Thesynthesis of these materials is described below in the process of theinvention. Preferred compounds within this group are those as describedin Formulas (IIa-d) wherein

R³-R⁸ are H; in Formula (IIa) wherein

R³-R⁵ are H and R⁶ is CH₃; and in Formula (IIe) wherein X² is —C(CH₃)₂—or —O—.

Another preferred embodiment of the invention is a compound as describedin Formula (I), wherein m is 1 and p is 0, and Formula (I) is selectedfrom the group of Formulas (IIIa-e):

Compounds as described in Formula (IIIa-e) are useful in polymerizableliquid crystal compositions, also of the invention. Many of thesecompounds exhibit nematic phases at or near room temperature (RT) andcan be mixed with other liquid crystal monomers to provide nematicphases over broad temperature ranges. Other compounds within this groupmay exhibit low melting points and can be used as reactive diluents andviscosity modifiers in liquid crystal mixtures. A preferred group ofcompounds is selected from those as described in Formula (Ma) whereinR¹-R⁶ is H. Another preferred group of compounds are those as describedin Formula (Ma) wherein R¹ and R² are H; one of the groups R³-R⁶ is CH₃;and three of the group R³-R⁶ are H. The synthesis of these compounds isdescribed below in the process of the invention. Especially preferredmaterials are those as described in Formula (Ma) wherein R³-R⁶ are H andR¹ and R² are H.

Another preferred embodiment of the invention is a compound as describedin Formula (I) wherein m and p are equal to 1, and Formula (I) isselected from the group of Formulas (IVa-e):

Compounds as described in Formula (IVa-e) are useful in polymerizableliquid crystal compositions, also of the invention. Many of thesecompounds exhibit broad nematic phases and can be mixed with otherliquid crystal monomers to provide nematic phases over broad temperatureranges. A preferred group of compounds are those as described in Formula(IVa) wherein B¹ and B² are R¹¹-substituted-1,4-phenyl; and R¹ and R²are each independently H or CH₃ Within this group a more preferred groupis wherein one of the group R³-R⁶ is Cl or CH₃; and three of the groupR³-R⁶ are H. Within these preferred groups more preferred are thosecompounds wherein n1 and n2 are, independently, integers 3 to 10. Thesynthesis of these materials is described below in the process of theinvention.

Another embodiment of this invention is a process for preparing thecompounds as described in Formula (I), such as the compounds asdescribed in Formula (IIa-f), (IIIa-e) and (IVa-e). This processcomprises (a) providing one or more organic polyol(s) wherein eachpolyol comprises at least two hydroxyl groups and at least twocovalently bonded carbon atoms, each hydroxyl group is bonded to adifferent carbon atom within an organic polyol; (b) reacting the organicpolyol(s) with one or more functionalized alkyl acid(s) or acidhalide(s) of the Formula (V):

wherein X is Cl, Br or —OH; X¹ is selected from the group: Cl, Br, I,-OMs (wherein Ms is methanesulfonyl), -OTs (wherein, Ts istoluenesulfonyl), and -OTf (wherein Tf is trifluoromethanesulfonyl); andn is an integer equal to 3 to 20; and a first reaction solvent at afirst reaction temperature to provide one or more polyfunctionalizedaryl alkanoate ester(s) and a first spent reaction mixture; (c) reactingthe one or more polyfunctionalized aryl alkanoate ester(s) with a(meth)acrylate salt in the presence of a phase transfer catalyst, and asecond reaction solvent at a second reaction temperature; to provide oneor more poly (meth)acrylate-aryl alkanoate ester(s) and a second spentreaction mixture. Preferably, the process step (b) further comprises theuse of a base, and when X is —OH, further comprises a carbodiimidedehydrating agent. Preferably, step (c) further comprises the use of oneor more radical inhibitors.

In various embodiments of the process of this invention, the polyol(s)may be selected from the group of compounds of Formulas (VIa-e):

wherein R³-R¹⁰ and X² are as described above. This embodiment of theprocess can be used to provide compounds of Formula (IIa-f) describedabove. Specific diols of Formula (VIa-f) useful and preferred in theprocess include: hydroquinone, methylhydroquinone, chlorohydroquinone,4,4′-dihydroxybiphenyl, 2,6-dihydroxynapthalene,1,5-dihydroxynapthalene, Bisphenol A, 6F-Bisphenol A, 4,4′-oxydiphenol,and trans-1,4-cyclohexanediol.

In other embodiments of the process of this invention, the polyol(s) mayinclude one or more ester diols selected from the group of compounds ofFormulas (VIIa-g):

wherein R³-R¹¹ are as described above. This embodiment of the processcan be used to provide compounds of Formula (IIIa-e) described above.Specific ester diols of Formula (VIIa-g) useful and preferred in theprocess include: 4-hydroxyphenyl 4-hydroxybenzoate,2-methyl-4-hydroxyphenyl 4-hydroxybenzoate, 3-methyl-4-hydroxyphenyl4-hydroxybenzoate, 2-chloro-4-hydroxyphenyl 4-hydroxybenzoate,

-   3-chloro-4-hydroxyphenyl 4-hydroxybenzoate, 2-fluoro-4-hydroxyphenyl    4-hydroxybenzoate, 3-fluoro-4-hydroxyphenyl 4-hydroxybenzoate,    2-phenyl-4-hydroxyphenyl 4-hydroxybenzoate, 3-phenyl-4-hydroxyphenyl    4-hydroxybenzoate,-   6-hydroxynaphthyl 4-hydroxybenzoate, 5-hydroxynaphtyl    4-hydroxybenzoate, 4-(4′-hydroxybiphenyl) 4-hydroxybenzoate,    trans-4-hydroxycyclohexyl 4-hydroxybenzoate,    trans-4-hydroxycyclohexyl 4-hydroxy-3-methoxybenzoate,    4-hydroxyphenyl 4-hydroxy-3-methoxybenzoate,    2-methyl-4-hydroxyphenyl 4-hydroxy-3-methoxybenzoate,-   3-methyl-4-hydroxyphenyl 4-hydroxy-3-methoxybenzoate,    2-chloro-4-hydroxyphenyl 4-hydroxy-3-methoxybenzoate,    3-chloro-4-hydroxyphenyl 4-hydroxy-3-methoxybenzoate,    4-hydroxyphenyl 4-hydroxy-3-methylbenzoate, 2-methyl-4-hydroxyphenyl    4-hydroxy-3-methylbenzoate, and 3-methyl-4-hydroxyphenyl    4-hydroxy-3-methylbenzoate.

Other ester diols useful and preferred in the process that providespecific compounds as described by Formula (VIIe) derived from6-hydroxy-2-napthalene carboxylic acid are:6-hydroxynapthalene-2-carboxylic acid 4-hydroxyphenyl ester (CAS No.[17295-17-9]), 6-hydroxynapthalene-2-carboxylic acid2-methyl-4-hydroxyphenyl ester, 6-hydroxynapthalene-2-carboxylic acid3-methyl-4-hydroxyphenyl ester, 6-hydroxynapthalene-2-carboxylic acid2-chloro-4-hydroxyphenyl ester, and 6-hydroxynapthalene-2-carboxylicacid 3-chloro-4-hydroxyphenyl ester.

Other ester diols useful and preferred in the process that providespecific compounds as described in Formula (VIIg) derived from4′-hydroxy-4-biphenyl carboxylic acid include:4′-hydroxybiphenyl-4-carboxylic acid 4-hydroxyphenyl ester,4′-hydroxybiphenyl-4-carboxylic acid 2-methyl-4-hydroxyphenyl ester,4′-hydroxybiphenyl-4-carboxylic acid 3-methyl-4-hydroxyphenyl ester,4′-hydroxybiphenyl-4-carboxylic acid 2-chloro-4-hydroxyphenyl ester, and4′-hydroxybiphenyl-4-carboxylic acid 3-chloro-4-hydroxyphenyl ester.

In another preferred embodiment of the process of the invention, thepolyol(s) may include one or more diester diol(s) selected from thegroup of compounds of Formulas (VIIIa-f):

wherein R³-R¹¹ are as described above. This embodiment of the processcan be used to provide compounds as described in Formula (IVa-e)described above. Specific diester diols of Formula (VIIIa-f) useful andpreferred in the process include compounds listed in Table 1 that arespecific examples of compounds of Formula (VIIIa-f).

Preferred functionalized alkyl acid halide(s) as described in Formula(V) are acid chlorides (X═Cl) wherein X¹ is Br. When the organic polyolis a diol, the amount of the functionalized alkyl acid halide(s) to beused is preferably about 1.8 to about 2.5 equivalents, and morepreferably about 2.0 to about 2.2 equivalents, based on the amount ofthe diol. In a preferred embodiment in step (b), the one or morefunctionalized alkyl acid halide(s) comprise two or more functionalizedalkyl acid halides, and said step (b) provides a mixture of at leastthree polyfunctionalized aryl alkanoate esters. In a preferred case, instep (b) the one or more functionalized alkyl acid halides(s) comprisestwo functionalized alkyl acid halide(s) in a molar ratio of about 0.05:1to about 1:1; and said step (b) provides a mixture of at least threepolyfunctionalized aryl alkanoate ester(s). This process, or derivationsthereof using three or more functionalized alkyl acid halide(s), is aconvenient and preferred process to provide complex mixtures of thecompounds of the invention.

The first reaction solvent can be any solvent known in the art to beuseful in performing acid halide condensations with alcohols, includingalkyl ethers such as tetrahydrofuran (THF), dioxane or dimethoxyethane;alkyl esters such as ethyl acetate or butyl acetate; hydrocarbons suchas xylenes or toluene; halogenated hydrocarbons such as1,2-dichloroethane oe dichloromethane; and amides such asdimethylformamide or dimethylacetamide (DMAc). A preferred firstreaction solvent is THF.

The (meth)acrylate salt useful in step (c) can be derived fromneutralization of the corresponding (meth)acrylate acid includingmethacrylic acid, acrylic acid, 2-chloroacrylic acid, and2-fluoroacrylic acid. The base used in the neutralization can be analkali metal base, for instance potassium carbonate and bicarbonate;sodium carbonate and bicarbonate; lithium carbonate and bicarbonate; andcesium carbonate and bicarbonate; to provide an alkali metal(meth)acrylate salt. The base can be an alkali earth metal base, forinstance magnesium, calcium or barium carbonate, to provide an alkaliearth metal (meth)acrylate salt. The base also can be an amine base, andparticularly a hindered amine base such as a tertiary aliphatic,aromatic or heterocyclic amine as described above; to provide anammonium (meth)acrylate salt. Preferred (meth)acrylate salts for step(c) are selected from the group: potassium (meth)acrylate and ammonium(meth)acrylates selected from the group: triethylammonium.

The (meth)acrylate salt can be provided from commercial sources; it canbe prepared in a separate process step and used directly or purified byone or more methods known in the art such as washing, filtering, drying,recrystallizing, or precipitating the salt; or it can be made in situ byneutralization of a (meth)acrylate acid with a base. In a preferredembodiment of the invention, the (meth)acrylate salt is provided bymixing (meth)acrylic acid and an alkali metal carbonate selected fromthe group: potassium hydrogen carbonate and potassium carbonate, in amolar ratio of about 1:1 to about 1:5, respectively, in said secondreaction solvent.

In a preferred embodiment of the process, the amount of (meth)acrylatesalt to be used is about 2.0 to about 10.0 equivalents per equivalent ofthe polyfunctionalized aryl alkanoate ester(s). Preferably the(meth)acrylate salt is an acrylate salt.

The phase transfer catalyst that may be used in step (c) is a substancethat, being at least partly present in or wetted by a first (usuallyorganic) phase, promotes reaction between a reactant in the first phaseand a reactant that it transfers to the first phase from a second phase,usually an aqueous or a solid phase. After reaction, the phase transfercatalyst is released for transferring further reactant. Suitably thephase transfer catalyst is a quaternary ammonium or phosphonium salt,preferably containing bulky organic groups, usually alkyl or aralkylgroups, to make it soluble in the organic phase. It is preferred thatthe phase catalyst is a tetraalkyl or aralkyl (e.g. benzyl) trialkylammonium or phosphonium salt in which the total number of carbon atomsattached to each nitrogen or phosphorus atom is at least 4. It isespecially preferred that the number should be in the range of from 16to 40. Other substances suitable for use herein as the phase transfercatalyst include those reviewed by E. V. Dehmlow in Angewante Chemie,(International Edition), 13, 170 (1974).

Quaternary ammonium salts suitable for use as the phase transfercatalyst herein include: cetyltrimethylammonium bromide,dicetyldimethylammonium chloride, octyltributylammonium bromide,trioctylmethylammonium chloride (available as Aliquat™ 336),benzyldimethyllaurylammonium chloride, benzyltriethylammonium chloride,dilauryldimethylammonium chloride, tetrabutylammonium bromide,tetrabutylammonium hydrogen sulfate and tetrabutylammonium iodide.Quaternary phosphonium salts suitable for use as the phase transfercatalyst herein include cetyltripropylphosphonium bromide andtriphenylethylphosphonium bromide. Other phase transfer catalysts thatmay be used include crown ethers and polyethylene glycol variants. Thephase transfer catalyst may be present in an amount ranging from about0.001 to about 0.9 mole equivalents, and preferably about 0.1 to about0.5 mole equivalents, of the polyfunctionalized aryl alkanoate ester(s).A preferred phase transfer catalyst is selected from the group:tetrabutylammonium iodide, tetrabutylammonium bromide, and tetraheptylammonium bromide; and crown ethers selected from the group: 18-crown-6,CAS No. [17455-13-9]; benzo-18-crown-6, CAS No. [14078-24-9];15-crown-5, CAS No. [33100-27-5]; and benzo-15-crown-5, CAS No.[140-44-3].

The second reaction solvent can be any solvent known in the art to beuseful in performing nucleophilic displacement of —X¹ with a(meth)acrylate salt. However, there is a preference for particularsecond reaction solvents that are aprotic in structure, and have adipole moment of about 3.5 or less. Solvents that are aprotic instructure are those that are devoid of active hydrogens such as hydroxylor acid functionality. Solvents having these characteristics providehigh rates of conversion of the polyfunctionalized aryl alkanoateester(s) to product while maintaining a very low level of undesiredester cleavage products. Preferred second reaction solvents includethose selected from the group: alkyl ethers including tetrahydrofuran,dioxane and dimethoxyethane; ketones including acetone and 2-butanone;alkyl esters including butyl acetate and ethyl acetate; andacetonitrile. In a preferred embodiment, the second reaction solvent maybe the first spent reaction mixture.

The first reaction temperature and second reaction temperature arereaction temperatures that give a reasonable rate of reaction with aminimum of by-products. The first reaction temperature generally isbetween −30° C. and about 50° C., and preferably about 0° C. to aboutroom temperature (RT, e.g. 25° C.). The second reaction temperature isgenerally about RT to about 120° C., and preferably about 50° C. toabout 100° C.

A base, when used in step (b), can include an inorganic base, forinstance an alkali metal or alkali earth metal hydroxide, carbonate orbicarbonate; or an organic base such as an amine base that has at leasttwo aliphatic groups, or in which the N atom is in a cycloaliphatic oraromatic ring, substituted in a manner that induces steric crowdingaround the N atom. Typically the amine base will be of low watersolubility and have a pK_(a) of the conjugate acid of about 10. Thus, itmay be a heteroaromatic base such as pyridine or a substituted pyridine,for example 2,6-dimethylpyridine; or it may be a secondary amineproviding it is sufficiently sterically hindered. An example of asuitable secondary amine is 2,2,6,6-tetramethyl-piperidine. Preferably,however, it is a tertiary amine of formula R¹²R¹³R¹⁴N wherein R¹², R¹³and R¹⁴ are each independently C1-C10 alkyl groups or C3-C6 cycloalkylgroups. The alkyl groups may be straight or branched chain. Examples ofsuitable alkyl groups include methyl, ethyl, isopropyl, n-propyl,n-butyl, sec-butyl and tert-butyl. Suitable tertiary amines of formulaR¹²R¹³R¹⁴N are, for example, N,N-diisopropylethylamine,N,N-dimethylaniline, triethylamine, t-butyldimethylamine,N,N-diisopropylmethylamine, N,N-diisopropylisobutylamine,N,N-diisopropyl-2-ethylbutylamine, tri-n-butylamine. Preferred are aminebases selected from the group: triethylamine, diisopropylethylamine,tributyl amine, pyridine, and 2,6-dimethylpyridine. The base ispreferably present in an amount of about 0.8 to about 5 equivalents perequivalent of the functionalized alkyl acid halide(s).

When the base used in step (b) is an amine base, a by-product of thereaction is an amine salt such as an amine hydrochloride. In a preferredembodiment the amine salt is removed from the first spent reactionmixture by, for instance, filtering the reaction mixture. This is aconvenient and preferred process wherein the second reaction solvent caninclude the first reaction solvent. In another embodiment, the one ormore polyfunctionalized aryl alkanoate ester(s) provided by step (b) canbe separated from the first spent reaction mixture by a variety ofmethods known in the art. Preferred methods include any one or more ofthe steps: filtering the amine salt by-product; precipitating thereaction mixture into water and filtering; partitioning the reactionmixture with water and/or organic solvents; washing with reactionmixture with water; drying the reaction mixture with a drying agent;removal of solvent by evaporation, chromatography, crystallizationand/or recrystallization of the one or more polyfunctionalized arylalkanoate ester(s); or washing the crude product with one or moresolvents which selectively remove byproducts without dissolving the oneor more polyfunctionalized aryl alkanoate ester(s).

When used in step (b), a suitable carbodiimide dehydrating agent may beany diimide commonly used in coupling acids with alcohols and phenols. Apreferred carbodiimide for step (b) is dicyclohexylcarbodiimide

A radical inhibitor, when used in step (c), may include any radicalinhibitor known to inhibit radical polymerization reactions of(meth)acrylate groups including 2,6-di-tert-butylphenol,2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol,2-methyl-6-tert-butylphenol, 2,4,6-tri-tert-octylphenol,2,4-dimethyl-6-tert-butylphenol, 2-tert-butyl-6-(α-methylbenzyl)phenol,2,4-di-tert-octylphenol, 2,6-di-tert-butyl-4-methoxyphenol,2,6-di-tert-octyl-4-decoxyphenol, 2-tert-butyl-4-chlorophenol,2,6-di-tert-butyl-4(N,N′-dimethylaminomethyl-phenol),2,2′-methylene-bis(4-methyl-6-tert-butylphenol),2,2′-methylene-bis(4-ethyl-6-tert-butylphenol),2,2′-methylene-bis(4-methyl-6-nonylphenol),4,4′methylenebis(2,6-di-tert-butylphenol),4,4′-bis(2,6-di-tert-butylphenol),4,4′-bis(2-methyl-6-tert-butylphenol),4,4′-isopropylidenebis(2,6-di-tert-butylphenol), 1,4-hydroquinone,4-methoxyphenol and the like; phosphorus compounds such astri(nonylphenyl) phosphate, tridecyl phosphite, and the like;naphthol-based compounds such as 1,2-dihydroxynaphthalene,1-amino-2-naphthol, 1-nitro-2-naphthol and the like; amine compoundssuch as trimethylamine, phenyl-β-naphthylamine, p-phenylenediamine,mercaptoethylamine, N-nitrosodimethylamine, benzotriazoles,phenothiazine, halo-dihydro-2,2,4-trimethylquinone and the like; orsulfur compounds such as dilaurylthio dipropionate, dilauryl sulfide and2-mercaptobenzimidazole. The above list is not intended to beexhaustive; numerous classes of compounds that inhibit formation ofradicals in organic materials are well known, and can be used in thepractice of this process. The radical inhibitor can be a singlecompound, or a mixture or combination of two or more of such compounds.The preferred radical inhibitors are selected from the group:2,6-di-tert-butyl-4-methylphenol, phenothiazine and tridecyl phosphate.

In another embodiment, the process further comprises separating the oneor more poly(meth)acrylate-aryl alkanoate ester(s) provided by step (c)from the second spent reaction mixture. This can be done by a variety ofmethods known in the art including any one or more of the steps:filtering the second spent reaction mixture; precipitating the reactionmixture into water and filtering; partitioning the reaction mixture withwater and/or organic solvents; washing the reaction mixture with water;drying the reaction mixture with a drying agent; removal of solvent byevaporation, chromatography, crystallization and/or recrystallization ofthe one or more poly(meth)acrylate-aryl alkanoate ester(s); and washingthe crude product with one or more solvents that selectively removebyproducts without dissolving the one or more polyfunctionalized arylalkanoate ester(s).

Another embodiment of this invention is a process for preparing thecompounds of Formula (I) wherein m and/or p is equal 2. The processcomprises (a) providing one or more polyol(s) selected from the group ofthose described by: Formula (VIIa-g) and (VIIIa-f); and (b) reacting thepolyol(s) with one or more (meth)acrylate aryl acid halides of the ofthe Formula (IXa-c):

wherein X is Cl or Br, n1 is an integer 3-20; and R¹ and R¹¹ are asdescribed above; and a first reaction solvent at a first reactiontemperature, as described above, to provide one or morepoly(meth)acrylate aryl alkanoate ester(s) of Formula (I) wherein mand/or p=2. Preferably step (b) includes the use of a base and one ormore radical inhibitors, as described above.

The preparation of (meth)acrylate aryl acid halides of Formula (IX) isdescribed in various examples as set forth below. In the processesdescribed above, the contents of the reaction mixture are used in atleast an amount that is sufficient to enable the reaction to proceed toprovide the stated product at a rate and with a yield that iscommercially useful.

The compounds of this invention, such as the compounds of Formulas(IIIa-e) and (IVa-e), are useful in polymerizable liquid crystalcompositions. Many of these compounds exhibit nematic phases uponmelting. They can be mixed together or with other liquid crystalmonomers to provide nematic phases over broad temperature ranges at ornear room temperature. Several compounds of various embodiments of thisinvention are listed in Tables 2 and 3 below with their correspondingthermal transitions that define their respective nematic phases.Mixtures of compounds of various embodiments of the invention are listedin Table 4 below with their corresponding thermal transitions thatdefine their respective nematic phases.

The compounds provided by this invention generally have importantattributes that are different from conventional polymerizable liquidcrystal bis (meth)acrylates. Conventional polymerizable liquid crystalbis(meth)acrylates of the general formula

(C—I), as prepared in Makromol. Chem. 190, 2255-2268 (1989);Macromolecules, 1988, 31, 5940; Makromol. Chem. 192, 59-74 (1991); WO1998/047979; J. Polym. Sci.: Part A: Polym. Chem., Vol. 37, 3929-3935(1999); Makromol. Chem. 190, 3201-3215 (1989); U.S. Pat. No. 5,833,880;DE 4,408,170; EP 261,712; EP 331,233 B1; EP 397,263 B1; and JP1994/016616A, and references cited therein, comprise ether groups (—O—)linking a core mesogen to flexible spacers and the polymerizable(meth)acrylates.

The synthetic methods used to prepare these conventional polymerizableliquid crystals are well documented. The thermal transitions of severalpolymerizable liquid crystal his (meth)acrylates of general formula(C—I) are listed in Table 5 below.

As illustrated in Comparative Example 4, the synthetic methods used toprepare the conventional his (meth)acrylates of general formula (C—I)are not useful for preparing the compounds provided by this invention.Furthermore, in comparison of their respective nematic phases, it isclear that the compounds provided by this invention unexpectedly exhibitnematic phases over significantly broader temperature ranges than theirconventional (—O— linkage) counterparts of general formula (C—I). Forinstance, Compound 24 exhibits a nematic phase between 10 and 30° C., a20° C. range, versus Comparative Compound 1-C exhibiting a nematic phasebetween 47 and 50° C., a 3° C. range. Compound 14 exhibits a nematicphase between 50 and 152° C., a 102° C. range, versus ComparativeCompound 6-C, which exhibits a nematic phase from 93 to 124° C., a rangeof 31° C. Compound 9 exhibits a nematic phase between 46 and 130° C., arange of 84° C., versus Comparative Compound 7-C, which exhibits anematic phase from 86 to 116° C., a range of 30° C. In addition, thecompounds provided by this invention exhibit lower melting points thanthe conventional his (meth) acrylates of formula (C—I). The lowestmelting point for a liquid crystalline compound as described by Formula(IVa-e) is 43° C., exhibited by Compound 15. This may be compared toComparative Compound 8-C, which exhibits a melting point of 57° C.Compound 17 also exhibits a melting point of 43° C., as compared toComparative Compound 9-C, which exhibits a melting point of 66° C.

Furthermore, liquid crystal mixtures comprising compounds provided bythis invention exhibit nematic phases over significantly broadertemperature ranges and lower melting temperatures than theirconventional (—O— linkage) counterparts corresponding to Formula (C—I).Mixture 9 exhibits a nematic phase from −24 to 149° C., a range of 173°C., as compared to Comparative Mixture 5-C, which exhibits a nematicphase from 60 to 97° C., a range of 37° C.

In contradistinction to these previous materials, another embodiment ofthe invention is a liquid crystal composition comprising at least onecompound of Formula (I), and in a further embodiment the liquid crystalcomposition includes at least one chiral compound. Two or more compoundsas provided by this invention can be mixed together to form apolymerizable nematic composition. Compounds as provided by thisinvention can also be mixed with conventional nematic liquid crystals orpolymerizable liquid crystals to form polymerizable nematiccompositions. Compounds as provided by this invention can further bemixed with chiral compounds, including polymerizable and/ornon-polymerizable chiral monomers and/or polymerizable and/ornon-polymerizable chiral nematic liquid crystals, to form polymerizabletwisted nematic compositions, also an embodiment of the invention.Preferred liquid crystal compositions comprise at least one compound asdescribed by Formula (IIIa-e). Other preferred liquid crystalcompositions comprise at least one compound as described by Formula(IVa-e).

Chiral compounds, including cholesteryl esters or carbonate, such asbenzoate esters, alkyl esters and alkyl carbonates of cholesterol, areknown to exhibit cholesteric phases and are known to be useful ininducing chirality in a nematic phase to produce a twisted nematicphase. Cholesteryl esters useful for incorporation into liquid crystalcompositions of this invention include cholesteryl benzoate, cholesteryl4-alkylbenzoates and cholesteryl 4-alkoxybenzoates wherein the alkyl andalkoxy groups are C1 to C8 straight or branched chain alkyl groups,cholesteryl propionate, cholesteryl butanoate, cholesteryl hexanoate,cholesteryl octanoate, cholesteryl decanoate, cholesteryl undecanoate,cholesteryl dodecanoate, cholesteryl hexadecanoate, and cholesteryloctadecanoate. Cholesteryl carbonates useful for this purpose includephenyl cholesteryl carbonate, 4-alkylphenyl cholesteryl carbonates,4-alkoxyphenyl cholesteryl carbonates, and alkyl cholesteryl carbonateswherein the alkyl or alkoxy groups are C1 to C8 straight or branchedchain alkyl groups.

In one embodiment of a composition of this invention, the incorporatedchiral compounds are polymerizable chiral monomers and includepolymerizable cholesterol derivatives as described in U.S. Pat. No.4,637,896; polymerizable terpenoid derivatives as described in U.S. Pat.No. 6,010,643; polymerizable derivatives wherein the chiral center is anasymmetric carbon atom of a branched alkyl chain as described in U.S.Pat. No. 5,560,864; polymerizable derivatives of vicinal diols orsubstituted vicinal diols as described in U.S. Pat. No. 6,120,859 andU.S. Pat. No. 6,607,677; and polymerizable chiral compounds as describedin U.S. Pat. Nos. 6,723,395, 6,217,792, 5,942,030, 5,885,242, and5,780,629. The references listed above in this paragraph is eachincorporated in its entirety as a part hereof.

A preferred group of polymerizable chiral monomers for use in thecompositions of this invention are those of Formula (X):

wherein R¹ and R² are each independently selected from the group: H, F,Cl and CH₃; n1 and n2 are each independently integers 3 to 20; q and rare each independently integers 0, 1 or 2 with the proviso that q+r is≧1; D is a divalent chiral radical selected from the group:

and B³ and B⁴ are each divalent radicals independently selected from thegroup: R¹¹-substituted-1,4-phenyl, wherein R¹¹ is H, —CH₃ or —OCH₃;2,6-naphthyl; and4,4″-biphenyl; provided that when q+r=3, at least one of B³ and B⁴ isR⁴-substituted-1,4-phenyl; and when q+r=4, at least two of B³ and B⁴ areR⁴-substituted-1,4-phenyl. Preferably R¹ and R² are independently H, orCH₃; and n1 and n2 are independently an integer 3 to 10.

Choices may be made from within and among the prescribed ranges for thevariable radicals and substituents such that the compound of Formula (X)is, for example, either symmetric or asymmetric.

Another preferred group of polymerizable chiral monomers for practicingthis invention are those of Formula (XI):

wherein R¹ is selected from the group: H, F, Cl and CH₃; E is selectedfrom the group: —(CH₂)_(n3)—, —(CH₂)_(n4)O—, and —(CH₂CH₂O)_(n5)—; n3and n4 are each integers 3 to 20; n5 is an integer 1 to 4; and y is aninteger 0 or 1.

Chiral compounds suitable for use in a composition as provided by thisinvention are also described in U.S. Provisional Application No.60/787,829, filed Mar. 31, 2006, and entitled “Chiral Compounds, andLiquid Crystal Compositions and Polymer Networks Derived Therefrom”,which is incorporated in its entirety as a part hereof for all purposes.

The liquid crystal compositions provided by this invention are mixturesuseful in preparing polymer networks that exhibit the fixed opticalproperties of nematic or twisted nematic polymer networks. A polymernetwork as provided by this invention is one or more polymerizedlayer(s) comprising a liquid crystal composition that may be fabricatedin a form such as polymerized films, coatings, castings and prints,including patterned, unpatterned, variable and nonvariable opticalproperties, and that can be made by a wide variety of methods asdisclosed, for instance, in U.S. Pat. Nos. 4,637,896, 6,010,643 and6,410,130, each of which is incorporated in its entirety as a parthereof.

In particular, one preferred method for making a polymer networkcomprises: providing a polymerizable liquid crystal mixture, in the formof a liquid crystal or isotropic phase, with a polymerization initiator,preferably a radical initiator; applying the liquid crystal mixture toone or more substrates, where the substrate(s) may optionally comprisean alignment layer, to provide a layer of liquid crystal; optionallytreating the layer to provide a desired liquid crystal phase; andpolymerizing the liquid crystal phase, preferably by exposing the liquidcrystal phase to actinic radiation. Actinic radiation includes, forexample, heat, microwave radiation, UV and visible light, and electronbeam and other radiation.

The liquid crystal compositions provided by various embodiments of thisinvention can include a radical initiator. Although the radicalinitiator is preferably a photoinitiator useful in conductingphotochemical polymerizations, such initiators are not required whencuring is performed by electron beams. Examples of suitablephotoinitiators are isobutyl benzoin ether,2,4,6-trimethylbenzoyldiphenylphosphine oxide, 1-hydroxycyclohexylphenyl ketone,2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)furan-1-one, mixtures ofbenzophenone and 1-hydroxycyclohexyl phenyl ketone,2,2-dimethoxy-2-phenylacetophenone, perfluorinated diphenyltitanocenes,2-methyl-1-(4-[methylthio]phenyl)-2-(4-morpholinyl)-1-propanone,2-hydroxy-2-methyl-1-phenylpropan-1-one, 4-(2-hydroxyethoxy)phenyl2-hydroxy-2-propyl ketone, 2,2-diethoxyacetophenone,4-benzoyl-4′-methyldiphenyl sulfide, ethyl 4-(dimethylamino)benzoate,mixtures of 2-isopropylthioxanthone and 4-isopropylthioxanthone,2-(dimethylamino)ethyl benzoate, d,l-camphorquinone,ethyl-d,l-camphorquinone, mixtures of benzophenone and4-methylbenzophenone, benzophenone, 4,4′-bisdimethylaminobenzophenone,triphenylsulfonium hexafluorophosphate or mixtures of triphenylsulfoniumsalts. Preferably the photoinitiators are present at a level of about0.1 wt % to about 3 wt % based on the total weight of the polymerizableliquid crystal mixture.

Forming a liquid crystal layer in a polymer network from a compound ofthis invention can be accomplished by any method that gives a uniformlayer, or if desired, a patterned or non-uniform layer. Coating,including rod-coating, extrusion coating, gravure coating andspin-coating, spraying, printing, blading, knifing, or a combination ofmethods, can be used. Coating and knifing are preferred methods. Manycommercial coating machines, devices such as a coating rod and knifeblade, and printing machines can be used to apply the liquid crystalmixture as a liquid crystal or isotropic phase.

The ability of a twisted nematic phase to reflect light is dependentupon the alignment or texture of the twisted nematic phase. For manyapplications wherein a high degree of transparency is required outsidethe reflection band, or in applications that require very well definedreflection bands, a high degree of uniformity in a planar or homogeneousalignment is required. Discontinuities and domain boundaries in a planaralignment can cause a high degree of haze and degradation of thereflection band. A high degree of uniformity in planar alignment can beaccomplished with a combination of alignment layers and/or mechanicalshearing of the twisted nematic phase during and/or after application tothe substrate(s). Alignment layers typically are polymers that areapplied to substrates and mechanically buffed with a rubbing cloth oroptically aligned with polarized light. The buffing or optical alignmentallows the liquid crystal molecules applied to the interface to align inone direction. Useful polyimide alignment layers, for example, aredescribed in U.S. Pat. No. 6,887,455. Alignment of twisted nematicphases by coating of dilute liquid crystal mixtures is described in U.S.Pat. No. 6,410,130.

Treating the liquid crystal layer to provide a desired liquid crystalphase can include steps such as cooling or heating the liquid crystallayer, for instance to achieve a desired phase or optical property;application of a mechanical shear to the liquid crystal layer, forinstance by application of a knife blade to the liquid crystal layer orshearing two or more substrates wherein the liquid crystal layer isinterposed; or vibration, sonication or other form of agitation to thesubstrate(s).

Another preferred method for making a polymer network comprises:providing an isotropic solution comprising a polymerizable liquidcrystal mixture, a polymerization initiator, preferably aphotoinitiator, and a carrier solvent; applying the isotropic solutionto one or more substrate(s), preferably where the substrate(s) comprisesan alignment layer, to provide an isotropic layer; removing the carriersolvent and, optionally, treating the layer, to provide a desired liquidcrystal phase; and polymerizing the liquid crystal phase, preferably byexposing the liquid crystal phase to actinic radiation. Procedures suchas these are more fully described in U.S. Pat. Nos. 6,010,643 and4,637,896 wherein preparation of a liquid crystal layer using twosubstrates to form a cell is set forth. In a similar vein, U.S. Pat.Nos. 4,637,896 and 6,410,130 describe the preparation of a liquidcrystal layer from an isotropic solution, followed by polymerization.

Where a carrier solvent is used with the liquid crystal composition,coating and spraying are preferred methods for applying the isotropicsolution. Removing the carrier solvent can be accomplished by allowingthe carrier solvent to evaporate, with or without heating and/orapplication of a vacuum. Allowing the carrier solvent to evaporate alsomay be accompanied and/or followed by application of a mechanical shearto the liquid crystal layer, as described above. Examples of suitablecarrier solvents are linear or branched esters, especially aceticesters, cyclic ethers and esters, alcohols, lactones, aliphatic andaromatic hydrocarbons, such as toluene, xylene and cyclohexane,chlorinated hydrocarbons, such as dichloromethane,1,1,2,2-tetrachloroethane, and also ketones, amides,N-alkylpyrrolidones, especially N-methylpyrrolidone. Additional examplesof useful solvents include tetrahydrofuran (THF), dioxane, methyl ethylketone (MEK), and propylene glycol monomethyl ether acetate.

Liquid crystal compositions as provided by this invention may furthercomprise small amounts of a polymerizable diluent that may include, forexample, 2-ethoxyethyl acrylate, diethylene glycol diacrylate, ethyleneglycol dimethacrylate, diethylene glycol dimethacrylate, triethyleneglycol dimethacrylate, diethylene glycol monomethyl ether acrylate,phenoxyethyl acrylate, tetraethylene glycol dimethacrylate,pentaerythritol tetraacrylate and ethoxylated pentaerythritoltetraacrylate.

Liquid crystal compositions as provided by this invention may furthercomprise small amounts of typical additives such as one or more ofsurfactants, leveling agents, viscosity modifiers, wetting agents,defoamers and UV stabilizers. Selection will often be based uponobserved coating and alignment quality and the desired adhesion of thefinal polymer network to the substrate and other layers. Typicalsurfactants comprise siloxy-, fluoryl-, alkyl- and alkynyl-substitutedsurfactants. These include the Byk® (Byk Chemie), Zonyl® (DuPont),Triton® (Dow), Surfynol® (Air Products) and Dynol® (Air Products)surfactants.

A liquid crystal polymer network as provided by this invention can becharacterized and differentiated from conventional polymerizable liquidcrystal bis(meth)acrylates of the general Formula (C—I), as disclosed inMakromol. Chem. 190, 2255-2268 (1989) and U.S. Pat. No. 5,833,880 andreferences cited therein, by comparison of their IR absorptionproperties. Networks obtained upon photopolymerization of polymerizableliquid crystal bis(meth)acrylates of the general formula (C—I) containaryl acrylate and alkyl alkanoate type ester linkages wherein R¹⁵ is alinear, branched, or cyclic aliphatic chain and Ar is a conventionalsubstituted or unsubstituted aromatic substituent. Polymerizable liquidcrystal bis(meth)acrylates as provided by various embodiments of thisinvention contain the two aforementioned classes of ester linkages, butalso contain aryl alkanoate type linkages. The ester stretchesassociated with aryl arylate and alkyl alkanoate type ester linkages arereported to be coincidental, while the stretch frequency for arylalkanoate type linkages is reported to appear at approximately 20-30cm⁻¹ higher frequency (Pretsch, Clerc, Seibl, Simon, Spectral Data forStructure Determination of Organic Compounds, Springer-Verlag, BerlinHeidelberg, 2^(nd) Ed., 1989, pp. I141-I142).

FIG. 1 displays IR spectra of crosslinked networks derived fromComparative Mixture 1-C, and Mixture 6, a composition provided by thisinvention. Comparative Mixture 1-C and Mixture 6 display nearlycoincidental ester absorptions at 1723 and 1727 cm⁻¹, respectively.However, Mixture 6 displays an additional absorption at 1756 cm⁻¹associated with the unique presence of aryl alkanoate linkages,consistent with literature predictions.

The ability of twisted nematic phases to selectively reflect light inthe infrared, visible or ultraviolet region is useful in manyapplications. When the propagation direction of plane polarized orunpolarized light is along the helical axis of the twisted nematiclayer, the wavelength of maximum reflection, λ₀, is governed by theequationλ₀=n_(a)p,wherein n_(a) is the average of n_(o) and n_(e), and n_(o) and n_(e) aredefined as the ordinary and extraordinary refractive indicesrespectively, of the twisted nematic phase measured in the propagationdirection and p is the pitch of the helix (the distance the helix takesto repeat itself). Light outside the vicinity of λ₀ is essentiallyunaffected in transmission. For light with a wavelength in the vicinityof wavelength λ₀, the twisted nematic phase exhibits selectivereflection of the light such that approximately 50% of the light isreflected and approximately 50% of the light is transmitted, with boththe reflected and transmitted beams being substantially circularlypolarized. A right handed helix reflects right handed circularlypolarized light and transmits left handed circularly polarized light.The bandwidth Δλ of this reflected wavelength band centered about λ₀ canbe determined by the formula Δλ=λ₀·Δn/n_(a), where Δn=n_(e)−n_(o),reflecting the birefringence present in liquid crystal materials. Thepitch p can be tuned effectively by manipulating the amount of chiraldopant, the twisting power of the dopant and selection of the nematicmaterials. The pitch is sensitive to to temperature, unwinding ortightening with a change in temperature; and to electric fields,dopants, and other environmental considerations. Thus, in the twistednematic phase, manipulation of the pitch, and thus the wavelength ofmaximum reflection, can be accomplished with a wide variety of tools.Furthermore, the bandwidth Δλ of the reflected wavelength band also canbe manipulated in the manner described in U.S. Pat. No. 5,506,704 andU.S. Pat. No. 5,793,456.

Polymer networks as provided by this invention can be made eitherflexible or brittle depending on crosslinking Brittle films, forexample, can be flaked and the flakes used as pigments in a variety ofinks or paints for use in cosmetics and automobile paint. The films canbe combined with other pigments or pigment layers, for instance blacklayers that act to enhance the brilliance of the reflected light.

Polymer networks as provided by this invention are useful as opticalelements or components of an optical element. An optical element is anyfilm, coating or shaped object that is used to modify thecharacteristics of light. The modifications produced by optical elementsinclude changes in the intensity of light through changes intransmission or reflectivity, changes in wavelength or wavelengthdistribution, changes in the state of polarization, changes in thedirection of propagation of part or all of the light, or changes in thespatial distribution of intensity by, for example, focusing,collimating, or diffusing the light. Examples of optical elementsinclude linear polarizers, circular polarizers, lenses, mirrors,collimators, diffusers, reflectors and the like. One specific example ofan optical element is a layer of a cholesteric network as provide bythis invention that reflects light within the vicinity of λ₀, employedin a window structure.

An optical element prepared from a polymer network as provided by thisinvention may be used as a component in a multilayer laminate, one formof which may be a laminated article. In one embodiment, the opticalelement may be provided in the form of a sheet that has a thickness ofgreater than about 10 mils (0.25 mm), or about 20 mils (0.50 mm) orgreater, where the total thickness of all components from which thelaminate is composed may be a thickness of about 30 mils (0.75 mm) orgreater to ensure adequate penetration resistance commonly regarded as afeature of safety laminates. Polymeric sheets useful for such purposemay be formed by any suitable process such as extrusion, calendering,solution casting or injection molding.

A polymeric sheet to be used as an interlayer within a laminate may havea roughened surface to effectively allow most of the air to be removedfrom between the surfaces of the laminate during the lamination process.This may be accomplished, for example, by mechanically embossing thesheet after extrusion, as described above, or by melt fracture duringextrusion of the sheet and the like. This rough surface is onlytemporary and particularly functions to facilitate deairing duringlaminating after which it is melted smooth from the elevated temperatureand pressure associated with autoclaving and other lamination processes.

In an embodiment where the optical element to be used in a laminate is apolymeric film, the film may be treated to enhance the adhesion to acoating or to a polymeric sheet or both. This treatment may take anysuitable form known such as adhesives, primers, such as silanes, flametreatments, plasma treatments, electron beam treatments, oxidationtreatments, corona discharge treatments, chemical treatments, chromicacid treatments, hot air treatments, ozone treatments, ultraviolet lighttreatments, sand blast treatments, solvent treatments, and the like andcombinations thereof. A film suitable for use herein as an opticalelement may have a thickness of about 10 mils (0.25 mm) or less, or athickness of between about 0.5 mils (0.012 millimeters (mm)), to about10 mils (0.25 mm), or a thickness of about 1 mil (0.025 mm) to about 5mils (0.13 mm)

In a further embodiment, a process to produce a multilayer laminateaccording to this invention provides a polymeric sheet laminated to apolymeric film that is coated with the twisted nematic liquid crystallayer. The polymeric sheet may be lightly bonded to the film with thetwisted nematic liquid crystal through a nip roll bonding process. Thecomponents may be heated to a temperature sufficient to promotetemporary fusion bonding, i.e., to cause the surfaces of the polymericsheet or the polymeric film to become tacky. Suitable temperatures arewithin the range of about 50° C. to about 120° C., with the preferredsurface temperatures reaching about 65° C. The film with the twistednematic liquid crystal is fed along with the polymeric sheet through niprolls where the two layers are merged together under moderate pressureto form a weakly bonded laminate. Generally the bonding pressure will bewithin the range of about 10 psi (0.7 kg/sq cm), to about 75 psi (5.3kg/sq cm), and is preferably within the range of about 25 psi (1.8 kg/sqcm), to about 30 psi (2.1 kg/sq cm). After bonding, the laminate ispassed over a series of cooling rolls which ensure that the laminatetaken up on a roll is not tacky. Laminates made through this processwill have sufficient strength to allow handling by laminators who mayproduce further laminated articles, such as glass laminates, whichencapsulate this laminate.

A multi-layer laminate may also be formed by an autoclave processeswherein a glass sheet, an interlayer composed of a polymeric sheet, apolymeric film with the twisted nematic liquid crystal (either in theform of a coated layer or of a film), a second polymeric sheet, and asecond glass sheet are laminated together under heat and pressure and avacuum (for example, in the range of about 27-28 inches (689-711 mm)Hg), to remove air.

In addition to a layer of a twisted nematic liquid crystal, whether as apolymeric sheet or as a polymeric film (either in the form of a coatedlayer or a film), a multilayer laminate as provided by this inventionmay include additional layers, such as other polymeric sheets, othercoated or uncoated polymeric films, half-wave plates and absorptivelayer. The additional layers may be glass or rigid transparent plasticsheets, such as, for example, polycarbonates, acrylics, polyacrylates,cyclic polyolefins, such as ethylene norbornene polymers,metallocene-catalyzed polystyrenes and the like and combinationsthereof. Metal or ceramic plates may also be suitable, if transparencyis not required for the laminate. The term “glass” is meant to includenot only window glass, plate glass, silicate glass, sheet glass, andfloat glass, but also includes colored glass, specialty glass whichincludes ingredients to control, for example, solar heating, coatedglass with, for example, sputtered metals, such as silver or indium tinoxide, for solar control purposes and other specialty glasses. The typeof glass to be selected for a particular laminate depends on theintended use.

An absorptive layer may also comprise part of a laminate as providedherein. The absorptive layer may be in the form of a discrete film. Inother embodiments the absorptive layer may be in the form of a coatingon one or more of the twisted nematic liquid crystal layers, thepolymeric sheets, the polymeric films and the rigid sheets. In stillother embodiments the absorptive layer may be incorporated into one ormore of the twisted nematic liquid crystal layers, the polymeric sheets,the polymeric films and the rigid sheets.

The present invention is further defined in the following examples. Itshould be understood that these examples, while indicating preferredembodiments of the invention, are given by way of illustration only.From the above discussion and these examples, one skilled in the art canascertain the essential characteristics of this invention, and withoutdeparting from the spirit and scope thereof, can make various changesand modifications of the invention to adapt it to various uses andconditions.

In the following examples, thermal transitions are given in degreesCentigrade. The following notations are used to describe the observedphases: K=crystal,

N=nematic, S=smectic, TN*=twisted nematic, X=unidentified phase,I=isotropic,

P=polymerized. The thermal transitions and phase assignments were madewith differential scanning calorimetry and hotstage optical microscopy.Unless noted otherwise, the phase behavior refers to the first heatingcycle.

The following materials are used in the examples of the invention.Compound 3, a chiral dopant used in the chiral nematic mixtures of theinvention was prepared in the following manner:

4-Hydroxybenzoic acid (80 g), isosorbide (40 g), p-toluenesulfonic acid(2 g), and xylenes (500 mL) were combined in a flask equipped with aDean-Stark trap, condenser and mechanical stirrer. The reaction mixturewas heated to reflux for 7 hrs at which time an additional charge ofp-toluenesulfonic acid (1.0 g) was added and the mixture heated back toreflux. After 2.5 hrs, the reaction was allowed to cool to roomtemperature. The xylenes were decanted and the solids were taken up in500 mL ethyl acetate, and washed with a 1% (w/v) sodium bicarbonatesolution. The solvent was removed under reduced pressure, providingCompound 1. ¹H NMR (DMSO-d₆, 400 MHz) δ 3.88-3.98 (m, 4H), 4.58 (d,J=4.9 Hz, 1H), 4.93 (t, J=5.3 Hz, 1H), 5.27 (br s, 1H), 5.32 (q, J=4.5Hz, 1H), 6.85 (d, J=8.8 Hz, 2H), 6.87 (d, J=8.8 Hz, 2H), 7.81 (d, J=8.8Hz, 2H), 7.84 (d, J=8.8 Hz, 2H), 10.36 (s, 2H).

A mixture of Compound 1 (30 g), THF (200 mL), and triethylamine (48 mL)was cooled to 0° C. A mixture of 6-bromohexanoyl chloride (36.5 g) andtetrahydrofuran (150 mL) was added dropwise over 25 minutes. Afterstirring for 2 hrs the reaction was partitioned between water anddiethyl ether and the organics were washed with dilute HCl, water,dried, filtered, and concentrated. The crude mixture was crystallizedfrom isopropyl alcohol to provide Compound 2. ¹H NMR (CDCl₃, 500 MHz)d1.59 (m, 4H), 1.80 (m, 4H), 1.93 (m, 4H), 2.60 (t, J=7.4 Hz, 2H), 2.61(t, J=7.4 Hz, 2H), 3.43 (t, J=6.7 Hz, 2H), 3.44 (t, J=6.7, 2H), 4.07 (m,4H), 4.66 (app d, 1H), 5.04 (app t, 1H), 5.41 (app q, 1H), 5.48 (app d,1H), 7.16 (d, J=8.9 Hz, 2H), 7.18 (d, J=8.9 Hz, 2H), 8.04 (d, J=8.9 Hz,2H), 8.11 (d, J=8.8 Hz, 2H).

To a mixture of Compound 2 (40 g), potassium bicarbonate (48.7 g),tetrabutylammonium iodide (8.0 g), 2,6-di-tert-butyl-4-methylphenol(1.74 g), and THF (500 mL), was added acrylic acid (11.2 g). The mixturewas heated to reflux for 6.5 hrs and stirred at RT for 16 h. The mixturewas diluted with ethyl ether and washed with water. The organics weredried, filtered, concentrated, and then taken up in hot isopropylalcohol. On cooling solids precipitated and were filtered to provideCompound 3. ¹H NMR (CDCl₃, 400 MHz) δ 1.52 (m, 4H), 1.75 (m, 4H), 1.81(m, 4H), 2.60 (t, J=7.4 Hz, 2H), 2.61 (t, J=7.4 Hz, 2H), 4.07 (m, 4H),4.191 (t, J=6.5 Hz, 2H), 4.194 (t, J=6.5 Hz, 2H), 4.66 (app d, J=4.7 Hz,1H), 5.05 (app t, J=5.2 Hz, 1H), 5.41 (app q, J=5.2 Hz, 1H), 5.48 (br s,1H), 5.82 (br d, J=10.4 Hz, 2H), 6.12 (app dd, J=17.3, 10.4 Hz, 2H),6.40 (app d, J=17.3 Jz, 2H), 7.16 (d, J=8.4, 2H), 7.18 (d, J=8.4 Hz,2H), 8.04 (d, J=8.8 Hz, 2H), 8.10 (d, J=8.8 Hz, 2H).

Compound 6, a chiral dopant used in the chiral nematic mixtures of theinvention, was prepared in the following manner:

A mixture of 4-hydroxybenzoic acid (40 g), isomannide (20 g), toluene(85 mL), diethylene glycol dimethyl ether (4 mL), and concentratedsulfuric acid (1 g) was heated to reflux for 8 h under nitrogen. Aftercooling to RT, ethyl acetate (200 mL) was added and the mixture stirredfor 2 h at 60° C. The mixture was cooled to RT and the resulting solidfiltered and dried to provide Compound 4. ¹H-NMR (DMSO-d₆, 500 MHz): δ3.85 (d of d, 2H, J_(HH)=9.3 Hz); 4.05 (d of d, 2H, J_(HH)=9.3 Hz); 4.78(m, 2H); 5.23 (m, 2H); 6.89 (d, 4H); 7.87 (d, 4H); 10.35 (s, 2H).

Compound 5 was prepared using an analogous procedure as was describedabove for the synthesis of Compound 2. ¹H NMR (DMSO-d₆, 500 MHz): δ 1.50(m, 4H); 1.69 (m, 4H); 1.86 (m, 4H); 2.64 (t, 4H, J_(HH)=7.2 Hz); 3.56(t, 4H, J_(HH)=6.6 Hz); 3.90 (d of d, 2H, J_(HH)=9.1 Hz); 4.07 (d of d,2H, J_(HH)=9.2 Hz); 4.82 (m, 2H); 5.29 (m, 2H); 7.31 (m, 4H); 8.06 (m,4H).

Compound 6 was prepared using an analogous procedure as was describedabove for the synthesis of Compound 3. ¹H NMR (CDCl₃, 500 MHz) δ 1.52(m, 4H), 1.75 (m, 4H), 1.81 (m, 4H), 2.60 (t, J=7.4 Hz, 4H), 3.99 (dd,J=9.4, 6.5 Hz, 2H), 4.13 (dd, J=9.4, 6.5 Hz, 2H), 4.20 (t, J=6.6 Hz,4H), 4.87 (dd, J=4.1, 1.3 Hz, 2H), 5.33 (m, 2H), 5.82 (dd, J=10.5, 1.4Hz, 2H), 6.12 (dd, J=17.3, 10.4 Hz, 2H), 6.40 (dd, J=17.3, 1.4 Hz, 2H),7.18 (d, J=8.7 Hz, 4H), 8.12 (d, 8.7 Hz, 4H).

Example 1

This example illustrates the formation of Compound 9, a liquid crystalmonomer of one embodiment of the invention.

A mixture of 240.0 g 4-hydroxybenzoic acid, 100.2 g methylhydroquinone,6 g p-toluenesulfonic acid, and 1.5 L xylenes was heated to reflux undera nitrogen atmosphere for a total of 26 h in a flask equipped with aDean-Stark trap, condenser and mechanical stirrer. Additionalp-toluenesulfonic acid (6.0 g portions) was added after 8 and 18 h aftercooling the reaction mixture RT. The final reaction mixture was cooledto RT, the solids collected and washed with hexanes. The solids wereslurried with hot acetone (600 mL) and cooled to RT, collected and driedto provide Compound 7. ¹H NMR (DMSO-d₆, 500 MHz) δ 2.16 (s, 3H), 6.93(d, J=8.8 Hz, 2H), 6.95 (d, J=8.8 Hz, 2H), 7.13 (m, 1H), 7.23 (m, 2H),7.99 (d, J=8.8 Hz, 2H), 8.02 (d, J=8.8 Hz, 2H), 10.51 (s, 2H).

A mixture of Compound 7 (100 g), THF (750 mL), and triethylamine (165mL) was cooled to 0° C. A mixture of 6-bromohexanoyl chloride (126.0 g)in tetrahydrofuran (400 mL) was added over about 0.75 h. The mixture wasstirred at 0° C. for 2 h and allowed to warm to RT, and stirred for 2 h.The mixture was poured into 1.5 L water and hydrochloric acid (37%) wasadded until the mixture was pH 6. The mixture was stirred for 15 min andthe solids collected. The solids were rinsed with water, methanol andthen dried to provide Compound 8. ¹H NMR (CDCl₃, 500 MHz) δ 1.60 (m,4H), 1.81 (m, 4H), 1.95 (m, 4H), 2.25 (s, 3H), 2.62 (t, J=7.4 Hz, 2H),2.63 (t, J=7.4 Hz, 2H), 3.45 (t, J=6.8 Hz, 4H), 7.10 (dd, J=8.6, 2.7 Hz,1H), 7.14 (d, J=2.7, 1H), 7.19 (d, J=8.6 Hz, 1H), 7.24 (d, J=8.7 Hz,2H), 7.25 (d, J=8.7 Hz, 2H), 8.22 (d, J=8.7 Hz, 2H), 8.25 (d, J=8.7 Hz,2H).

To a mixture of Compound 8 (20.0 g), 25.1 g potassium bicarbonate, 5.14g tetrabutyl ammonium iodide, 1.04 g 2,6-di-tert-butyl-4-methylphenol,and THF (350 mL) was added 5.73 mL acrylic acid. The mixture was heatedat 65° C. for 9 h and then allowed to stir at RT overnight. The mixturewas partition between ether/water, and the ether layer washed withseveral portions of water. The ether layer was dried and the solventremoved and the product recrystallized from isopropanol to provideCompound 9 (17.25 g, 88%). ¹H NMR (CDCl₃, 500 MHz) δ1.54 (m=4H), 1.77(m, 4H), 1.83 (m, 4H), 2.25 (s, 3H), 2.624 (t, J=7.4 Hz, 2H), 2.629 (t,J=7.4 Hz, 2H), 4.21 (t, J=6.6, 4H), 5.82 (dd, J=10.4, 1.3 Hz, 2H), 6.13(dd, J=17.3, 10.4 Hz, 2H), 6.40 (dd, J=17.3, 1.3 Hz, 2H), 7.10 (dd,J=8.7, 2.7 Hz, 1H), 7.15 (d, J=2.7, 1H), 7.19 (d, J=8.7, 1H), 7.24 (d,J=8.6 Hz, 2H), 7.25 (d, J=8.6 Hz, 2H), 8.22 (d, 8.6 Hz, 2H), 8.25 (d,J=8.6 Hz, 2H).

Examples 2-10

Compounds 10 through 18 that are liquid crystal monomers of variousembodiments of the invention where prepared in a similar manner asdescribed in Example 1:

¹H NMR (CDCl₃, 500 MHz) δ 2.17 (m, 4H), 2.73 (t, J=7.3 Hz, 4H), 4.31 (t,J=6.3 Hz, 4H), 5.85 (dd, J=10.4, 1.4 Hz, 2H), 6.14 (dd, J=17.4, 10.4 Hz,2H), 6.43 (dd, J=17.4, 1.4 Hz, 2H), 7.26 (d, J=8.7 Hz, 4H), 7.28 (s,4H), 8.24 (d, J=8.7 Hz, 4H).

¹H NMR (CDCl₃, 500 MHz) δ 1.54 (m, 4H), 1.76 (m, 4H), 1.83 (m, 4H), 2.63(t, J=7.4 Hz, 4H), 4.20 (t, J=6.6 Hz, 4H), 5.82 (dd, J=10.5, 1.4 Hz,2H), 6.12 (dd, J=17.4, 10.5 Hz, 2H), 6.41 (dd, J=17.4, 1.4 Hz, 2H), 7.24(d, J=8.7 Hz, 4H), 7.28 (s, 4H), 8.23 (d, J=8.7 Hz, 4H).

¹H NMR (CDCl₃, 500 MHz) δ 1.28-1.47 (m, 24H), 1.67 (m, 4H), 1.77 (m,4H), 2.59 (t, J=7.5 Hz, 4H), 4.16 (t, J=6.7 Hz, 4H), 5.80 (dd, J=10.5,1.3 Hz, 2H), 6.12 (dd, J=17.4, 10.5 Hz, 2H), 6.39 (J=17.4, 1.3 Hz, 2H),7.24 (d, J=8.7 Hz, 4H), 7.28 (s, 4H), 8.23 (d, J=8.7 Hz, 4H).

¹H NMR (CDCl₃, 500 MHz) δ 2.17 (m, 4H), 2.26 (s, 3H), 2.73 (t, J=7.3 Hz,2H), 2.74 (t, J=7.3 Hz, 2H), 4.308 (t, J=6.2 Hz, 2H), 4.310 (t, J=6.2Hz, 2H), 5.858 (dd, J=10.5, 1.4 Hz, 1H), 5.860 (dd, J=10.5, 1.4 Hz, 1H),6.144 (dd, J=17.4, 10.5 Hz, 1H), 6.146 (dd, J=17.4, 10.5 Hz, 1H), 6.434(dd, J=17.4, 1.4 Hz, 1H), 6.437 (dd, J=17.4, 1.4 Hz, 1H), 7.10 (dd,J=8.6, 2.8 Hz, 1H), 7.15 (d, J=2.6, 1H), 7.19 (d, J=8.8 Hz, 1H), 7.25(d, J=8.8 Hz, 2H), 7.27 (d, J=8.8 Hz, 2H), 8.23 (d, J=8.8 Hz, 2H), 8.26(d, J=8.8 Hz, 2H).

¹H NMR (CDCl₃, 500 MHz) δ 1.86 (m, 8H), 2.25 (s, 3H), 2.66 (t, J=7.0 Hz,2H), 2.67 (t, J=7.0 Hz, 2H), 4.24 (t, J=6.2 Hz, 4H), 5.84 (dd, J=10.5,1.3 Hz, 2H), 6.14 (dd, J=17.4, 10.5 Hz, 2H), 6.42 (dd, J=17.4, 1.3 Hz,2H), 7.10 (dd, J=8.7, 2.6 Hz, 1H), 7.14 (d, 2.6 Hz, 1H), 7.19 (d, J=8.7Hz, 1H), 7.24 (d, J=8.8 Hz, 2H), 7.25 (d, J=8.8 Hz, 2H), 8.23 (d, J=8.8Hz, 2H), 8.25 (d, J=8.8 Hz, 2H).

¹H NMR (CDCl₃, 400 MHz) δ 1.55 (m, 4H), 1.77 (m, 4H), 1.84 (m, 4H), 1.95(s, 6H), 2.25 (s, 3H), 2.62 (t, J=7.4 Hz, 2H), 2.63 (t, J=7.4 Hz, 2H),4.19 (t, J=6.5 Hz, 4H), 5.56 (m, 2H), 6.11 (br s, 2H), 7.10 (dd, J=8.7,2.6 Hz, 1H), 7.14 (d, J=2.6 Hz, 1H), 7.19 (d, J=8.7 Hz, 1H), 7.23 (d,J=8.8 Hz, 2H), 7.24 (d, J=8.8 Hz, 2H), 8.22 (d, J=8.8 Hz, 2H), 8.25 (d,J=8.8 Hz, 2H).

¹H NMR (CDCl₃, 400 MHz) δ 1.25-1.47 (m, 24H), 1.67 (m, 4H), 1.78 (m,(4H), 2.25 (s, 3H), 2.59 (t, J=7.5 Hz, 2H), 2.60 (t, J=7.5 Hz, 2H), 4.16(t, J=6.7 Hz, 4H), 5.80 (dd, J=10.5, 1.3 Hz, 2H), 6.12 (dd, J=17.4, 10.5Hz, 2H), 6.39 (dd, J=17.4, 1.3 Hz, 2H), 7.10 (dd, J=8.7 Hz, 2.5 Hz, 1H),7.14 (d, J=2.5 Hz, 1H), 7.19 (d, J=8.7 Hz, 2H), 7.24 (d, J=8.7 Hz, 2H),7.25 (d, J=8.7 Hz, 2H), 8.22 (d, J=8.7 Hz, 2H), 8.25 (d, J=8.7 Hz, 2H).

¹H NMR (CDCl₃, 500 MHz) δ 1.54 (m, 4H), 1.76 (m, 4H), 1.83 (m, 4H),2.623 (t, J=7.4 Hz, 2H), 2.626 (t, J=7.4 Hz, 2H), 4.20 (t, J=6.5 Hz,4H), 5.82 (dd, J=10.5, 1.3 Hz, 2H), 6.12 (dd, J=17.4, 10.5 Hz, 2H), 6.40(dd, J=17.4, 1.3 Hz, 2H), 7.21 (dd, J=8.8, 2.7 Hz, 1H), 7.25 (d, J=8.7Hz, 2H), 7.26 (d, J=8.7 Hz, 2H), 7.34 (d, J=8.8 Hz, 1H), 7.41 (d, J=2.7Hz, 1H), 8.21 (d, J=8.7 Hz, 2H), 8.26 (d, J=8.7 Hz, 2H).

¹H NMR (DMSO-d₆, 500 MHz): δ 1.45 (m, 4H); 1.69 (m, 8H); 2.65 (t, 2H,J_(HH)=7.4 Hz); 4.14 (t, 4H, J_(HH)=6.5 Hz); 5.94 (d of d, 2H,J_(HH)=10.3 Hz); 6.18 (d of d, 2H, J_(HH)=17.3 Hz); 6.33 (d of d, 2H,J_(HH)=17.3 Hz); 7.15 (d, 4H); 7.36 (m, 8H); 8.19 (d, 4H).

Example 11

This example illustrates the formation of Compound 21, a liquid crystalmonomer of one embodiment of the invention.

A mixture of 6-hydroxy-naphtalene-2-carboxylic acid (20 g),methylhydroquinone (6 g), concentrated sulfuric acid (1 mL), and xylenes(125 mL) was heated to reflux for 8 h under nitrogen in a flask equippedwith a Dean-Stark trap, condenser and mechanical stirrer. About 2 mLwater was collected in the trap. The mixture was cooled to RT, filtered,the solids were rinsed with hexanes and then dried. The solids wereadded to 400 mL of DMAc and the mixture was heated to 60° C. and stirredfor 1 h. The mixture was cooled and the insoluble material was filteredoff. The filtrate volume was concentrated to ˜¼ volume and addeddrop-wise to 1 L of water and stirred for 2 h. The precipitate wasfiltered off and the crude product was dissolved in 200 mL acetone andboiled for 0.5 h. The mixture was cooled and stirred overnight at RT.The solids were filtered and the filtrate solution was added drop-wiseto 1 L of water and stirred for 1 h. The precipitate was filtered offand dried overnight to provide Compound 19. ¹H-NMR (DMSO-d₆, 500 MHz): δ2.25 (s, 3H); 7.2-7.4 (m, 7H); 7.8-7.9 (m, 2H); 8.0-8.1 (m, 4H); 8.75(d, 2H, J_(HH)=16 Hz); 10.3 (s, 2H broad).

Compound 20 was prepared using an analogous procedure as was describedabove for the synthesis of Compound 8. ¹H-NMR (DMSO-d₆, 500 MHz): δ 1.43(q, 4H, J_(HH)=7.4 Hz); 1.62 (q, 4H, J_(HH)=7.5 Hz); 1.77 (q, 4H,J_(HH)=7.3 Hz); 2.14 (s, 3H); 2.57 (t, 4H, J_(HH)=7.4 Hz); 3.46 (t, 4H,J_(HH)=6.6 Hz); 7.1-7.4 (m, 5H); 7.72 (m, 2H); 7.9-8.1 (m, 4H), 8.17 (m,2H); 8.80 (d, 2H, J_(HH)=20.6 Hz).

Compound 21 was prepared using an analogous procedure as was describedabove for the synthesis of Compound 9. The product was obtained in 76%isolated yield. ¹H-NMR (DMSO-d₆, 500 MHz): δ 1.48 (q, 4H, J_(HH)=7.3Hz); 1.72 (m, 8H, J_(HH)=7.5 Hz); 2.26 (s, 3H); 2.69 (t, 4H, J_(HH)=7.3Hz); 4.16 (t, 4H, J_(HH)=6.5 Hz); 5.94 (d of d, 2H, J_(HH)=10.3 Hz);6.20 (d of d, 2H, J_(HH)=17.2 Hz); 6.35 (d of d, 2H, J_(HH)=17.3 Hz);7.3-7.5 (m, 5H); 7.83 (m, 2H); 8.1-8.2 (m, 4H), 8.28 (d of d, 2H,J_(HH)=9.1 Hz); 8.92 (d, 2H, J_(HH)=16.6 Hz).

Example 12

This example illustrates the formation of Compound 24, a liquid crystalmonomer of one embodiment of the invention.

A mixture of 4-hydroxybenzoic acid (80 g), hydroquinone (64 g),p-toluenesulfonic acid (2 g), xylenes (500 mL) was heated to reflux in aflask equipped with a Dean-Stark trap, condenser and mechanical stirreruntil about 10 mL of water were collected. After cooling to roomtemperature the solids were filtered off, washed with hexanes, anddried. The obtained solids were placed into 600 mL of boiling acetoneand stirred for 30 min. The mixture was filtered hot to eliminate tracesof insoluble material. After cooling to room temperature the acetonesolution was yellow but transparent. 1500 mL of DI water were addedslowly to precipitate the product. The precipitated product was filteredoff and dried to provide Compound 22. ¹H NMR (CDCl₃, 500 MHz) δ 6.78 (d,8.9 Hz, 2H), 6.90 (d, J=8.8 Hz, 2H), 7.00 (d, J=8.9 Hz, 2H), 7.94 (d,J=8.8 Hz, 2H), 9.42 (s, 1H), 10.44 (s, 1H).

Compound 23 was prepared using an analogous procedure as was describedabove for the synthesis of Compound 8. ¹H NMR (CDCl₃, 500 MHz) δ1.59 (m,4H), 1.80 (m, 4H), 1.94 (m, 4H), 2.59 (t, J=7.4 Hz, 2H), 2.63 (t, J=7.4Jz, 2H), 3.441 (t, J=6.7 Hz, 2H), 3.446 (t, J=6.7 Hz, 2H), 7.14 (d,J=9.0 Hz, 2H), 7.22 (d, 9.0 Hz, 2H), 7.24 (d, 8.8 Hz, 2H), 8.22 (d, 8.8Hz, 2H).

Compound 24 was prepared using an analogous procedure as was describedabove for the synthesis of Compound 9. ¹H NMR (CDCl₃, 500 MHz) δ 1.52(m, 4H), 1.76 (m, 4H), 1.78 (m, 4H), 2.59 (t, J=7.4 Hz, 2H), 2.62 (t,J=7.4 Hz, 2H), 4.19 (t, J=6.6 Hz, 2H), 4.20 (t, J=6.6 Hz, 2H), 5.823(dd, 1H), 5.826 (dd, 1H), 6.122 (dd, 1H), 6.127 (dd, 1H), 6.404 (dd,1H), 6.407 (dd, 1H), 7.13 (d, J=8.6 Hz, 2H), 7.21 (d, J=8.6 Hz, 2H),7.23 (d, J=8.6 Hz, 2H), 8.21 (d, J=8.6 Hz, 2H).

Example 13

This example illustrates the formation of Compound 27, a liquid crystalmonomer of one embodiment of the invention.

A mixture of 6-hydroxy-naphtalene-2-carboxylic acid (20 g), hydroquinone(17 g), concentrated sulfuric acid (4 drops), and xylenes (125 mL) washeated to reflux for 8 hours and during this time two more 4-dropaliquots of sulfuric acid were added. After 2.0 mL of water werecollected in the trap the reaction was cooled to room temperature, thesolids were filtered, washed with hexanes, and dried. The material wassuspended into 300 mL of acetone and heated to reflux for 30 min. Themixture was filtered hot to remove insoluble materials and the clearsolution was poured into 1 L of water. The precipitated product wasfiltered off, washed with water, and dried. The purification proceduredescribed above was repeated once more to provide Compound 25. ¹H-NMR(DMSO-d₆, 500 MHz): δ 6.87 (m, 2H); 7.11 (m, 2H); 7.22-7.28 (m, 2H);7.9-8.1 (m, 3H); 8.69 (d, 1H, J_(HH)=1 Hz); 9.50 (s, 1H); 10.27 (s, 1H).

Compound 26 was prepared using an analogous procedure as was describedabove for the synthesis of Compound 8. ¹H-NMR (DMSO-d₆, 500 MHz) δ 1.52(m, 4H); 1.71 (m, 4H); 1.87 (m, 4H); 2.62 (t, 2H, J_(HH)=7.4 Hz); 2.68(t, 2H, J_(HH)=7.3 Hz); 3.57 (m, 4H); 7.25 (m, 2H); 7.40 (m, 2H); 7.46(m, 1H); 7.83 (d, 1H, J_(HH)=2 Hz); 8.1-8.3 (m, 3H); 8.87 (s, 1H).

Compound 27 was prepared using an analogous procedure as was describedabove for the synthesis of Compound 9. ¹H-NMR (DMSO-d₆, 500 MHz): δ 1.46(m, 4H); 1.69 (m, 8H); 2.62 (t, 2H, J_(HH)=7.3 Hz); 2.69 (t, 2H,J_(HH)=7.3 Hz); 4.15 (m, 4H); 5.94 (d of d, 2H, J_(HH)=10.3 Hz); 6.19 (dof d, 2H, J_(HH)=17.3 Hz); 6.34 (d of d, 2H, J_(HH)=17.2 Hz); 7.24 (m,2H); 7.40 (m, 2H); 7.46 (m, 1H); 7.83 (d, 1H, J_(HH)=2 Hz); 8.1-8.3 (m,3H); 8.88 (s, 1H).

Examples 14-15

Procedures similar to those used in preparation of Compounds 8 and 9(Example 1) were used to prepare Compounds 29 and 30, which are monomersprovided by various embodiments the invention.

¹H NMR (CDCl₃, 500 MHz) δ 1.58 (m, 4H), 1.78 (m, 4H), 1.92 (m, 4H), 2.16(s, 3H), 2.56 (t, J=7.4 Hz, 2H), 2.60 (t, J=7.4 Hz, 2H), 3.43 (t, J=6.7Hz, 4H), 6.91 (dd, J=8.6, 2.8 Hz, 1H), 6.96 (d, J=2.8 Hz, 1H), 6.99 (d,J=8.6 Hz, 1H).

¹H NMR (CDCl₃, 500 MHz) δ 1.52 (m, 4H), 1.74 (m, 4H), 1.81 (m, 4H), 2.56(t, J=7.5 Hz, 2H), 2.59 (t, J=7.5 Hz, 2H), 4.19 (t, J=6.55 Hz, 4H), 5.81(br d, J=10.5 Hz, 2H), 6.12 (app dd, J=17.3, 10.5 Hz, 2H), 6.39 (app dd,J=17.3, 1.4 Hz, 2H), 6.90 (dd, J=8.7, 2.7 Hz, 1H), 6.95 (d, J=2.7 Hz,1H), 6.99 (d, J=8.7 Hz, 1H).

¹H NMR (CDCl₃, 500 MHz) δ 1.51 (m, 4H), 1.66 (s, 6H), 1.74 (m, 4H), 1.79(m, 4H), 2.56 (t, J=7.3 Hz, 4H), 4.18 (t, J=6.5 Hz, 4H), 5.80 (dd,J=10.5, 1.3 Hz, 2H), 6.11 (dd, J=17.4, 10.5 Hz, 2H), 6.38 (dd, J=17.4,1.3 Hz, 2H), 6.96 (d, J=8.8 Hz, 4H), 7.21 (d, J=8.8 Hz, 4H).

Example 16

This example illustrates a process provided by the invention whereinCompound 9 is prepared directly from Compound 7, without isolation ofintermediate Compound 8.

Compound 7 (5.0 g) was combined with 60 mL of THF, and 8.3 mLtriethylamine. The solution was cooled to 0° C. and a solution of 6.3 g6-bromohexanoyl chloride in 40 mL THF was added dropwise over 20minutes. The reaction was stirred at 0° C. for 1.5 and then for twohours at RT. The solution was filtered and rinsed with 20 mL THF. Thereaction solution was then combined with 12.4 g potassium bicarbonate,2.03 g tetrabutylammonium iodide, 0.42 g2,6-di-tertbutyl-4-methylphenol, and 2.82 mL acrylic acid and heated atreflux open to air for 5.5 hours. The reaction was added to 250 mL waterand the pH adjusted to 5 using concentrated HCl. The product wasextracted with diethyl ether and then washed with water. The organicswere dried (MgSO₄) and then concentrated to provide a yellow oil. 100 mLhexanes was added and the mixture was cooled to 0° C. for 20 minutes toproduce a solid which was filtered and dried, providing Compound 9. The¹H NMR spectrum was identical to that obtained following the method ofExample 1.

Example 17

This example illustrates the formation of Mixture 1, a liquid crystalcomposition as provided by the invention, prepared by a process asprovided by the invention. The molar ratios are the nominal ratios basedon the reaction stoichiometry.

A mixture of Compound 7 (5.0 g), THF (60 mL), and 8.4 mL triethylaminewas cooled to 0° C., and a mixture of 4.29 g 6-bromohexanoyl chlorideand 1.87 g 4-bromobutyryl chloride in 50 mL THF was added dropwise over20 min. The reaction was stirred for an additional 1 h at 0° C. followedby 2 h at RT. The mixture was filtered and the filtered solids werewashed with 20 mL to THF. The filtrate was then combined with 12.4 gpotassium bicarbonate, 2.03 g tetrabutylammonium iodide, and 0.42 g2,6-di-tertbutyl-4-methylphenol. After stirring for 5 min at RT, acrylicacid (2.82 mL) was added. The mixture was heated to reflux, open to air,for 4 h. The mixture was stirred for an additional 14 h at RT. Water(250 mL) was added and pH adjusted to 6 using concentrated HCl. Theproduct was extracted into diethyl ether. The organics were washed withwater, dried (MgSO₄), filtered, and concentrated to a cloudy, yellowoil. The crude product was washed with 75 mL methanol for 30 min. Themethanol was decanted and hexanes (75 mL) was added. After stirring for30 min the hexanes was decanted and residual solvent removed to provideMixture 1. Phase behavior: X−29 N 131 I.

Example 18

This example illustrates the formation of Mixture 2, a chiral liquidcrystal composition prepared by a process as provided by the invention.

A mixture of 4.60 g Compound 7, 0.424 g Compound 1, 60 mL THF and 6.3 mLtriethylamine was cooled to 0° C. A solution of 4.83 g 6-bromohexanoylchloride and 1.40 g 4-bromobutyryl chloride in 40 mL THF was then addeddropwise over 20 minutes. The reaction was stirred for an hour at 0° C.before being stirred for an additional 2 h at RT. The reaction mixturewas filtered and the filtered solids were washed with 20 mL THF. Thefiltrate was then transferred to a fresh flask and 12.4 g potassiumbicarbonate, 2.03 g tetrabutylammonium iodide, and 0.42 g2,6-di-tertbutyl-4-methylphenol were added. After stirring for 5 minutesat room temperature 2.82 mL acrylic acid were added. The reactionmixture was heated to reflux, open to air, for 4 hours. After cooling toroom temperature, the reaction mixture was stirred for an additional 14hours at room temperature. The reaction mixture was added to 200 mL ofwater and then adjusted to pH 5 using concentrated HCl. The residue wasextracted into diethyl ether and the extract washed with water 3×,dried, filtered and concentrated to a yellow oil. The oil was washedwith isopropyl alcohol (75 mL), washed with hexanes (75 mL) and theresidual solvent removed to provide Mixture 2. Phase behavior: 1^(st)Heating=X−31 TN*110 I; 1^(st) Cooling=I 109 TN*−34X; 2 ^(nd)Heating=X−31 TN*111 I. Wavelength of Reflectance=797 nm.

Example 19

This example illustrates a method to prepare an achiral liquid crystalmixture, wherein each compound of the mixture was prepared separately.

Compound 9 (0.125 g) and Compound 11 (0.123 g) were combined anddissolved in methylene chloride. The solution was filtered (0.45 micronfilter), and solvent removed to provide Mixture 3.

Example 20

This example illustrates the method used to prepare a twisted nematicmixture wherein each compound was prepared separately.

An analogous procedure was followed as was described above for thepreparation of Mixture 3. DSC: 1^(st) Heating=K 55 TN*105 I; 1^(st)Cooling=I 104 TN*−53×; 2^(nd) Heating=X−31 TN*105 I. Wavelength ofreflectance=532 nm.

Example 21

This example illustrates the method used to prepare a twisted nematicmixture wherein each compound was prepared separately.

An analogous procedure was followed as was described above for thepreparation of Mixture 3. Phase behavior: 1^(st) heating=X−32 TN*94 I,1^(st) cooling: 185 TN*, 2^(nd) heating=TN*97 I. Wavelength ofReflectance=789 nm.

Example 22

This example illustrates the formation of a polymer network of theinvention derived from liquid crystal monomers of the invention.

Mixture 2 (0.5 g), Compound 24 (0.128 g), and Irgacure® 184 (0.013 g)were dissolved in 1,1,2,2-tetrachloroethane (1.19 mL) to provide Mixture6. A polyethylene terephthalate film was hand rubbed with a YoshikawaYA-20-R rubbing cloth. A small amount of Mixture 6 was coated by handusing a Wire Size 20 Wire Wound Lab Rod (Paul N. Gardner Company,Pompano Beach, Fla.). The wet coating was heated at 50° C. for 2 min andwas exposed with a Blak-Ray Long Wave UV Mercury Lamp (UVP Inc., Upland,Calif.) for 2 min under a nitrogen atmosphere. The infrared spectrum ofthe film is shown in FIG. 1.

Example 23

This example illustrates the preparation of a twisted nematiccomposition wherein the chiral monomer is a reactive cholesteryl estercompound. Compound 31 has been previously reported by Shibaev.Preparation of Compound 32 has been previously reported by Shannon(Marcromolecules 1983, 16, 1677-1678).

An analogous procedure was followed as was described above for thepreparation of Mixture 3. Phase behavior: 1^(st) Heating=X60 TN*95 I;1St Cooling=194 TN*; 2^(nd) Heating=TN*96 I. Wavelength ofreflectance=1015 nm.

Example 24

This example illustrates the synthesis of (meth)acrylate aryl acidhalides of Formula (IX).

6-Hydroxyhexanoic acid was first prepared following the procedurereported in PCT/JP2005/004389.

Caprolactone (100 g) was added to a mixture of potassium hydroxide (145g), methanol (110 mL), and THF (390 mL). The resulting mixture wasstirred at room temperature overnight. The solution was then acidifiedwith HCl and extracted with ethyl acetate. The combined organic layerswere washed with water, dried, filtered, and concentrated to obtain6-hydroxyhexanoic acid. ¹H NMR (CDCl₃, 500 MHz) δ 1.44 (m, 2H), 1.60 (m,2H), 1.68 (m, 2H), 2.37 (t, J=7.5 Hz, 2H), 3.66 (t, J=6.5 Hz, 2H), 5.80(br, 1 H).

6-Acryloyloxyhexanoic acid was prepared following the procedure reportedin PCT/JP2005/004389.

A mixture of 6-hydroxyhexanoic acid (10 g),2,6-di-tert-butyl-4-methylphenol (0.5 g), and dimethylacetamide (57 mL)was cooled to 0° C. Acryloyl chloride (17.2 g) was then added dropwise.After stirring for 3.5 hrs, pyridine (12 mL) and water (12 mL) wereslowly added. After stirring for another 2 hrs, the solution wasacidified with dilute HCl and extracted with ethyl acetate. The combinedorganic layer was washed with water, dried, filtered, and concentratedto afford 6-acryloyloxyhexanoic acid. ¹H NMR (CDCl₃, 500 MHz) δ 1.46 (m,2H), 1.70 (m, 4H), 2.37 (t, J=7.3 Hz, 2H), 4.17 (t, J=6.4 Hz, 2H), 5.82(d, J=10.4 Hz, 1H), 6.12 (dd, J=17.3, 10.5 Hz, 1H), 6.39 (d, J=17.3 Hz,1H), 11.59 (br, 1 H).

A mixture of 6-acryloyloxyhexanoic acid (5.0 g),2,6-di-tert-butyl-4-methylphenol (0.3 g), chloroform (30 mL), and DMF(10 drops) was cooled to 0° C. Oxalyl chloride (5.12 g) and chloroform(20 mL) were then added dropwise. After stirring for 3 hrs, the solventwas removed and the resulting acid chloride was re-dissolved in amixture of chloroform (20 mL) and tetrahydrofuran (20 mL). The acidchloride solution was then transferred to a mixture of4′-hydroxy-4-biphenylcarboxylic acid (5.76 g), triethylamine (5.2 mL),4-dimethylaminopyridine (0.13 g), 2,6-di-tert-butyl-4-methylphenol (0.3g), and tetrahydrofuran (55 mL) which had been cooled to 0° C. Afterstirring for 12 hrs, the reaction mixture was added to water, acidifiedwith dilute HCl, extracted with chloroform, dried, filtered, andconcentrated. The crude mixture was purified by washing withacetonitrile and isopropanol to obtain Compound 33. ¹H NMR (DMSO-d₆, 500MHz) δ 1.45 (m, 2H), 1.69 (m, 4H), 2.63 (t, J=7.4 Hz, 2H), 4.14 (t,J=6.6 Hz, 2H), 5.94 (app d, J=10.3 Hz, 1H), 6.18 (app dd, J=17.3, 10.4Hz, 1H), 6.33 (app d, J=17.3 Hz, 1H), 7.24 (m, 2H), 7.79 (m, 4H), 8.02(m, 2H), 12.95 (br, 1 H).

A mixture of Compound 33 (3.0 g), 2,6-di-tert-butyl-4-methylphenol (0.14g), tetrahydrofuran (20 mL), and DMF (6 drops) was cooled to 0° C.Oxalyl chloride (1.49 g) and tetrahydrofuran (20 mL) were then addeddropwise. After stirring for 7 hrs, the solvent was removed to providethe corresponding acid chloride.

Comparative Example 1

Comparative Examples 1-3 demonstrate that known processes for providingmeth(acrylate) functionality in molecules by halide displacement are notsufficient when bis(meth)acrylates comprising aryl alkanoate esters areto be provided.

Acrylate addition was performed using a literature procedure.

The conversion of Compound 8 to Compound 9 was attempted following theprocedure reported by Lander and Hegedus (J. Am. Chem. Soc. 1994, 116,8126-8132).

To a 25 mL round-bottom flask was added 0.3 g (0.418 mmol) of Compound8, 0.233 mL (1.67 mmol) triethylamine, and 5 mL dimethylformamideAcrylic acid (0.115 mL, 1.67 mmol) was then added. The reaction wasstirred for 19 hours at 25° C. The crude reaction mixture was dilutedwith ethyl acetate and washed three times with water. The organics weredried (MgSO₄) and then concentrated by rotary evaporation to provide0.23 g of a colorless oil. NMR analysis showed that only 39% of thealkyl bromides were converted to acryloxy groups. The aromatic esterframework remained intact.

Comparative Example 2

Acrylate addition was performed using a literature procedure.

The conversion of Compound 8 to Compound 9 was attempted following theprocedure reported by Craig and Imrie (Macromolecules, 1995, 28,3617-3624).

To a Schlenk tube was added 0.238 g (2.38 mmol) potassium bicarbonatefollowed by 0.17 mL acrylic acid. The mixture was stirred together for 5mins at 25° C. before 0.6 g (0.836 mmol) bis(4-(6-bromohexanoyl)-benzoicacid) ester of methyl hydroquinone, 0.002 g hydroquinone, and 10 mL DMFwere added. The reaction was heated to 100° C. for 14 hours. Thereaction mixture was diluted with methylene chloride and washed with 5%sodium hydroxide solution, followed by water. The organics were dried(MgSO₄) and then concentrated by rotary evaporation to provide a tanoil. NMR analysis indicated complete conversion of bromides toacryloyloxy groups, however there was extensive cleavage of the esterlinkages resulting in a product yield (NMR) of <30%.

Comparative Example 3

Acrylate addition was performed using patent procedure.

The conversion of Compound 8 to Compound 9 was attempted following theprocedure reported in U.S. Pat. No. 4,614,619. A mixture of Compound 8(0.6 g, 0.836 mmol), potassium acrylate (0.553 g, 5.016 mmol),tetrabutyl ammonium bromide (0.108 g, 0.3344 mmol),2,6-di-tert-buty-4-methyl phenol (0.013 g, 0.057 mmol), water (0.6 mL)and chloroform (0.3 mL) was heated at an oil bath temp of 112° C. for 40h. To the cooled reaction mixture was added 40 mL diethyl ether and 10mL methylene chloride and the organic phase washed with water 3×, driedover MgSO₄, filtered, and concentrated, providing a white solid. NMRanalysis indicated complete conversion of the bromides to acryloyloxygroups, however there was complete hydrolysis of the ester linkagesresulting in a product yield (NMR) of <5%.

Comparative Example 4

This example demonstrates that the methodology used to prepare theconventional ether linked materials (Formula C—I) is not applicable tothe preparation of the materials provided by the present invention. Thefirst step in the preparation of the materials of Formula C—I, asdisclosed in U.S. Pat. No. 5,833,880, Example 1, was followed, butreplacing 4-chlorobutyl acetate with 6-bromohexanoyl chloride.

As such, 3 g ethyl 4-hydroxybenzoate, 0.036 g potassium iodide, and 2.99g potassium carbonate were dissolved in 24 mL DMF, and 4.62 g6-bromohexanoyl chloride was added dropwise. The reaction was heated at90° C. for 10 hours, before being added to ice water. The productseparated as an oil, in contrast to the teachings of U.S. Pat. No.5,833,880, wherein a solid was isolated. The oily product was separatedfrom the water using an ether extraction. The ether was dried andremoved to provide 5.36 g of a yellow oil. NMR analysis indicated thepresence of a complex mixture of acylation and alkylation products. Theyellow oil was combined with 4.81 g potassium hydroxide and 36 mLethanol and heated to reflux for 3 hours. The reaction was added to icewater, acidified with concentrated HCl, filtered, washed with freshwater, and dried, to obtain 1.3 g of a white solid. NMR analysisindicated that the product was Compound 34, rather than the desired,Compound 35.

¹H-NMR of Compound 34: (DMSO-d₆, 400 MHz) δ 1.43 (m, 2H), 1.57 (m, 2H),1.73 (m, 2H), 2.23 (t, J=7.3 Hz, 2H), 4.03 (t, J=6.5 Hz, 2H), 6.99 (d,8.9 Hz, 2H), 7.88 (d, 8.9 Hz, 2H).

Comparative Example 5

Liquid crystal mixture Merck RMS03-009 (Comparative Mixture 1-C) waspurchased from Merck KGaA, Liquid Crystals, Darmstadt, Germany. Acoating was prepared using an analogous procedure as described above inExample 22. The infrared spectrum of the ether linked (—O—) polymernetwork is shown in FIG. 1.

TABLE 1

TABLE 2 Nematic Example Window Number Compound and First Heating PhaseBehavior (deg C) 12

20 13

92 23

N/A

TABLE 3 Nematic Example Window Number Compound and First Heating PhaseBehavior (deg C) 2

66 3

60 4

22 5

49 6

102 1

84 7

75 8

48 9

100 11

110

TABLE 4 Nematic Example Window Number Mixture and First Heating PhaseBehavior (deg C) 9

85

24

73

25

100

17

160

26

173

TABLE 5 Comparative Compounds and Mixtures Nematic Window Compound and1st Heating Phase Behavior (deg C)

 3

58

47

20

40

31

30

48

51

49 22

 8

48

37

References ⁽¹⁾ Macromolecules, 1988, 31, 5940 ⁽²⁾ Makromol. Chem. 192,59-74 (1991) ⁽³⁾ WO1998047979 ⁽⁴⁾ J. Polym. Sci.: Part A: Polym. Chem.,Vol. 37, 3929-3935 (1999) ⁽⁵⁾ Makromol. Chem. 190, 3201-3215 (1989) ⁽⁶⁾U.S. Pat. No. 5,833,880

Each of the formulae shown herein describes each and all of theseparate, individual compounds that can be formed in that formula by (i)selection from within the prescribed range for one of the variable,substituents or numerical coefficients while all of the other variableradicals, substituents or numerical coefficients are held constant, and(ii) performing in turn the same selection from within the prescribedrange for each of the other variable radicals, substituents or numericalcoefficients with the others being held constant. In addition to aselection made within the prescribed range for any of the variableradicals, substituents or numerical coefficients of only one of themembers of the group described by the range, a plurality of compoundsmay be described by selecting more than one but less than all of themembers of the group of radicals, substituents or numericalcoefficients. When the selection made within the prescribed range forany of the variable radicals, substituents or numerical coefficients isa subgroup containing (a) only one of the members of the group describedby the range, or (b) more than one but less than all of the members ofthe group, the selected member(s) are selected by omitting thosemember(s) of the whole group that are not selected to form the subgroup.The compound, or plurality of compounds, may in such event be describedas containing one or more variable radicals, substituents or numericalcoefficients each of which variable radicals, substituents or numericalcoefficients is defined by the members of the whole group, described bythe range for that variable radical, substituent or numericalcoefficient in the absence of the member(s) omitted to form thesubgroup.

Certain features of this invention are described herein in the contextof an embodiment that combines various such features together, whetheras described in the disclosure or in one of the drawings. The scope ofthe invention is not, however, limited by the description of onlycertain features within any particular embodiment, and the inventionalso includes (1) a subcombination of fewer than all of the features ofany described embodiment, which subcombination is characterized by theabsence of the features omitted to form the subcombination; (2) each ofthe features, individually, included within the combination of thedescribed embodiment; and (3) other combinations of features formed fromone or more or all of the features of the described embodiment togetherwith other features as disclosed elsewhere herein.

Where a range of numerical values is recited herein, the range includesthe endpoints thereof and all the individual integers and fractionswithin the range, and also includes each of the narrower ranges thereinformed by all the various possible combinations of those endpoints andinternal integers and fractions to form subgroups of the larger group ofvalues to the same extent as if each of those narrower ranges wasexplicitly recited. Where a range of numerical values is stated hereinas being greater than a stated value, the range is nevertheless finiteand is bounded on its upper end by a value that is operable within thecontext of the invention as described herein. Where a range of numericalvalues is stated herein as being less than a stated value, the range isnevertheless bounded on its lower end by a non-zero value.

In this specification, unless explicitly stated otherwise or indicatedto the contrary by the context of usage, where an embodiment of thisinvention is stated or described as comprising, including, containing,having, being composed of or being constituted by or of certain featuresor elements, one or more features or elements in addition to thoseexplicitly stated or described may be present in the embodiment. Analternative embodiment of this invention, however, may be stated ordescribed as consisting essentially of certain features or elements, inwhich embodiment features or elements that would materially alter theprinciple of operation or the distinguishing characteristics of theembodiment are not present therein. A further alternative embodiment ofthis invention may be stated or described as consisting of certainfeatures or elements, in which embodiment, or in insubstantialvariations thereof, only the features or elements specifically stated ordescribed are present.

In this specification, unless explicitly stated otherwise or indicatedto the contrary by the context of usage,

-   -   (a) amounts, sizes, formulations, parameters, and other        quantities and characteristics recited herein, particularly when        modified by the term “about”, may but need not be exact, and may        be approximate and/or larger or smaller than stated (as        desired), reflecting tolerances, conversion factors, rounding        off, measurement error and the like, as well as the inclusion        within a stated value of those values outside it that have,        within the context of this invention, functional and/or operable        equivalence to the stated value;    -   (b) all numerical quantities of parts, percentage or ratio are        given as parts, percentage or ratio by weight;    -   (c) use of the indefinite article “a” or “an” with respect to a        to statement or description of the presence of an element or        feature of this invention, does not limit the presence of the        element or feature to one in number;    -   (d) the words “include”, “includes” and “including” are to be        read and interpreted as if they were followed by the phrase        “without limitation” if in fact that is not the case; and    -   (e) the word “or”, as used herein, is inclusive; more        specifically, the phrase “A or B” means “A, B, or both A and B”;        and use of “or” in an exclusive sense is designated, for        example, by terms such as “either A or B” and “one of A or B”.

1. A process comprising: a) providing one or more organic polyol(s)comprising at least two hydroxyl groups and at least two covalentlybonded carbon atoms, each hydroxyl group being bonded to a differentcarbon atom within an organic polyol; b) reacting the organic polyol(s)with one or more functionalized alkyl acid(s) of the Formula (V):

wherein X is —OH; X¹ is selected from the group: Cl, Br, I, -OMs, -OTsand -OTf; and n is an integer equal to 3 to 20; and a first reactionsolvent at a first reaction temperature to provide one or morepolyfunctionalized aryl alkanoate ester(s) and a first spent reactionmixture; and c) reacting the one or more polyfunctionalized arylalkanoate ester(s) with a (meth)acrylate salt in the presence of a phasetransfer catalyst, and a second reaction solvent at a second reactiontemperature; to provide one or more poly(meth)acrylate-aryl alkanoateester(s) and a second spent reaction mixture.
 2. The process of claim 1wherein step (b) further comprises addition of a base; and step (c)further comprises addition of one or more radical inhibitors.
 3. Theprocess of claim 2 wherein the base is an amine base and is present inan amount of about 0.8 to about 5 equivalents of the functionalizedalkyl acid.
 4. A process comprising: a) providing one or more organicpolyol(s) comprising at least two hydroxyl groups and at least twocovalently bonded carbon atoms, each hydroxyl group being bonded to adifferent carbon atom within an organic polyol; b) reacting the organicpolyol(s) with one or more functionalized alkyl acid(s) or acidhalide(s) of the Formula (V):

wherein X is Cl, Br or —OH; X¹ is selected from the group: Cl, Br, I,-OMs, -OTs and -OTf; and n is an integer equal to 3 to 20; and a firstreaction solvent at a first reaction temperature to provide one or morepolyfunctionalized aryl alkanoate ester(s) and a first spent reactionmixture; and c) reacting the one or more polyfunctionalized arylalkanoate ester(s) with a (meth)acrylate salt in the presence of a phasetransfer catalyst, and a second reaction solvent at a second reactiontemperature; to provide one or more poly(meth)acrylate-aryl alkanoateester(s) and a second spent reaction mixture; wherein the secondreaction solvent is an aprotic solvent having a dipole moment of lessthan about 3.5; and the (meth)acrylate salt is selected from an alkalimetal salt or ammonium salt.
 5. A process comprising: a) providing oneor more organic polyol(s) comprising at least two hydroxyl groups and atleast two covalently bonded carbon atoms, each hydroxyl group beingbonded to a different carbon atom within an organic polyol; b) reactingthe organic polyol(s) with one or more functionalized alkyl acid(s) oracid halide(s) of the Formula (V):

wherein X is Cl, Br or —OH; X¹ is selected from the group: Cl, Br, I,-OMs, -OTs and -OTf; and n is an integer equal to 3 to 20; and a firstreaction solvent at a first reaction temperature to provide one or morepolyfunctionalized aryl alkanoate ester(s) and a first spent reactionmixture; c) reacting the one or more polyfunctionalized aryl alkanoateester(s) with a (meth)acrylate salt in the presence of a phase transfercatalyst, and a second reaction solvent at a second reactiontemperature; to provide one or more poly(meth)acrylate-aryl alkanoateester(s) and a second spent reaction mixture; d) separating the one ormore polyfunctionalized aryl alkanoate ester(s) from the first spentreaction mixture; and e) separating the one or morepoly(meth)acrylate-aryl alkanoate ester(s) from the second spentreaction mixture.
 6. The process of claim 1 wherein the second reactionsolvent comprises the first spent reaction mixture.
 7. A processcomprising: a) providing one or more organic polyol(s) comprising atleast two hydroxyl groups and at least two covalently bonded carbonatoms, each hydroxyl group being bonded to a different carbon atomwithin an organic polyol; b) reacting the organic polyol(s) with two ormore functionalized alkyl acid halides of the Formula (V):

wherein X is Cl, Br or —OH; X¹ is selected from the group: Cl, Br, I,—OMs, -OTs and -OTf; and n is an integer equal to 3 to 20; and a firstreaction solvent at a first reaction temperature to provide a mixture ofat least three polyfunctionalized aryl alkanoate esters and a firstspent reaction mixture; and c) reacting the mixture ofpolyfunctionalized aryl alkanoate ester(s) with a (meth)acrylate salt inthe presence of a phase transfer catalyst, and a second reaction solventat a second reaction temperature; to provide poly(meth)acrylate-arylalkanoate esters and a second spent reaction mixture.
 8. A processcomprising: a) providing one or more organic polyol(s) comprising atleast two hydroxyl groups and at least two covalently bonded carbonatoms, each hydroxyl group being bonded to a different carbon atomwithin an organic polyol; b) reacting the organic polyol(s) with one ormore functionalized alkyl acid(s) or acid halide(s) of the Formula (V):

wherein X is Cl, Br or —OH; X¹ is selected from the group: Cl, Br, I,-OMs, -OTs and -OTf; and n is an integer equal to 3 to 20; and a firstreaction solvent at a first reaction temperature to provide one or morepolyfunctionalized aryl alkanoate ester(s) and a first spent reactionmixture; and c) reacting the one or more polyfunctionalized arylalkanoate ester(s) with a (meth)acrylate salt in the presence of a phasetransfer catalyst, and a second reaction solvent at a second reactiontemperature; to provide one or more poly(meth)acrylate-aryl alkanoateester(s) and a second spent reaction mixture; wherein said(meth)acrylate salt is provided by mixing (meth)acrylic acid and analkali metal carbonate selected from potassium hydrogen carbonate orpotassium carbonate; in a molar ratio of about 1:1 to about 1:5,respectively, in said second reaction solvent; and said sufficientamount of (meth)acrylate salt is about 2.0 to about 10.0 equivalents ofthe polyfunctionalized aryl alkanoate ester(s).
 9. The process of claim1 wherein said polyol is a diol selected from the group of compounds ofFormulas (VIa-e):

wherein R³-R¹⁰ are selected from the group: H, C₁-C₈ straight orbranched chain alkyl, C₁-C₈ straight or branched chain alkyloxy, F, Cl,phenyl, —C(O)CH₃, CN and CF₃; and X² is a divalent radical selected fromthe group: —O—, —(CH₃)₂C—, and —(CF₃)₂C—.
 10. The process of claim 1wherein said polyol is an ester diol selected from the group ofmaterials of Formulas (VIIa-g):

wherein R³-R¹⁰ are selected from the group: H, C₁-C₈ straight orbranched chain alkyl, C₁-C₈ straight or branched chain alkyloxy, F, Cl,phenyl, —C(O)CH₃, CN and CF₃; and R¹¹ is H, —CH₃ or —OCH₃.
 11. Theprocess of claim 1 wherein said polyol is a diester diol selected fromthe group of compounds of Formulas (VIIIa-e):

wherein R³-R¹⁰ are selected from the group: H, C₁-C₈ straight orbranched chain alkyl, C₁-C₈ straight or branched chain alkyloxy, F, Cl,phenyl, —C(O)CH₃, CN and CF₃; and R¹¹ is H, —CH₃ or —OCH₃.